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* [PATCH 3/8] Add rewrite rules and tupdesc flags
@ 2018-06-18 12:34 Ildus Kurbangaliev <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Ildus Kurbangaliev @ 2018-06-18 12:34 UTC (permalink / raw)
Signed-off-by: Ildus Kurbangaliev <[email protected]>
---
src/backend/access/brin/brin_tuple.c | 2 +
src/backend/access/common/heaptuple.c | 27 +++++++++-
src/backend/access/common/indextuple.c | 2 +
src/backend/access/common/tupdesc.c | 20 ++++++++
src/backend/access/heap/heapam.c | 19 ++++---
src/backend/access/heap/tuptoaster.c | 2 +
src/backend/commands/copy.c | 2 +-
src/backend/commands/createas.c | 2 +-
src/backend/commands/matview.c | 2 +-
src/backend/commands/tablecmds.c | 69 ++++++++++++++++++++++++--
src/backend/utils/adt/expandedrecord.c | 1 +
src/backend/utils/cache/relcache.c | 4 ++
src/include/access/heapam.h | 3 +-
src/include/access/hio.h | 2 +
src/include/access/htup_details.h | 9 +++-
src/include/access/tupdesc.h | 7 +++
src/include/access/tuptoaster.h | 1 -
src/include/commands/event_trigger.h | 1 +
18 files changed, 157 insertions(+), 18 deletions(-)
diff --git a/src/backend/access/brin/brin_tuple.c b/src/backend/access/brin/brin_tuple.c
index a5bc6f5749..df391bcc78 100644
--- a/src/backend/access/brin/brin_tuple.c
+++ b/src/backend/access/brin/brin_tuple.c
@@ -96,6 +96,7 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple,
int keyno;
int idxattno;
uint16 phony_infomask = 0;
+ uint16 phony_infomask2 = 0;
bits8 *phony_nullbitmap;
Size len,
hoff,
@@ -187,6 +188,7 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple,
(char *) rettuple + hoff,
data_len,
&phony_infomask,
+ &phony_infomask2,
phony_nullbitmap);
/* done with these */
diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c
index 783b04a3cb..b05dee6195 100644
--- a/src/backend/access/common/heaptuple.c
+++ b/src/backend/access/common/heaptuple.c
@@ -177,6 +177,7 @@ fill_val(Form_pg_attribute att,
int *bitmask,
char **dataP,
uint16 *infomask,
+ uint16 *infomask2,
Datum datum,
bool isnull)
{
@@ -207,6 +208,9 @@ fill_val(Form_pg_attribute att,
**bit |= *bitmask;
}
+ if (OidIsValid(att->attcompression))
+ *infomask2 |= HEAP_HASCUSTOMCOMPRESSED;
+
/*
* XXX we use the att_align macros on the pointer value itself, not on an
* offset. This is a bit of a hack.
@@ -245,6 +249,15 @@ fill_val(Form_pg_attribute att,
/* no alignment, since it's short by definition */
data_length = VARSIZE_EXTERNAL(val);
memcpy(data, val, data_length);
+
+ if (VARATT_IS_EXTERNAL_ONDISK(val))
+ {
+ struct varatt_external toast_pointer;
+
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, val);
+ if (VARATT_EXTERNAL_IS_CUSTOM_COMPRESSED(toast_pointer))
+ *infomask2 |= HEAP_HASCUSTOMCOMPRESSED;
+ }
}
}
else if (VARATT_IS_SHORT(val))
@@ -268,6 +281,9 @@ fill_val(Form_pg_attribute att,
att->attalign);
data_length = VARSIZE(val);
memcpy(data, val, data_length);
+
+ if (VARATT_IS_CUSTOM_COMPRESSED(val))
+ *infomask2 |= HEAP_HASCUSTOMCOMPRESSED;
}
}
else if (att->attlen == -2)
@@ -304,7 +320,7 @@ void
heap_fill_tuple(TupleDesc tupleDesc,
Datum *values, bool *isnull,
char *data, Size data_size,
- uint16 *infomask, bits8 *bit)
+ uint16 *infomask, uint16 *infomask2, bits8 *bit)
{
bits8 *bitP;
int bitmask;
@@ -328,6 +344,7 @@ heap_fill_tuple(TupleDesc tupleDesc,
}
*infomask &= ~(HEAP_HASNULL | HEAP_HASVARWIDTH | HEAP_HASEXTERNAL);
+ *infomask2 &= ~HEAP_HASCUSTOMCOMPRESSED;
for (i = 0; i < numberOfAttributes; i++)
{
@@ -338,6 +355,7 @@ heap_fill_tuple(TupleDesc tupleDesc,
&bitmask,
&data,
infomask,
+ infomask2,
values ? values[i] : PointerGetDatum(NULL),
isnull ? isnull[i] : true);
}
@@ -752,6 +770,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
int bitMask = 0;
char *targetData;
uint16 *infoMask;
+ uint16 *infoMask2;
Assert((targetHeapTuple && !targetMinimalTuple)
|| (!targetHeapTuple && targetMinimalTuple));
@@ -864,6 +883,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
+ offsetof(HeapTupleHeaderData, t_bits));
targetData = (char *) (*targetHeapTuple)->t_data + hoff;
infoMask = &(targetTHeader->t_infomask);
+ infoMask2 = &(targetTHeader->t_infomask2);
}
else
{
@@ -882,6 +902,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
+ offsetof(MinimalTupleData, t_bits));
targetData = (char *) *targetMinimalTuple + hoff;
infoMask = &((*targetMinimalTuple)->t_infomask);
+ infoMask2 = &((*targetMinimalTuple)->t_infomask2);
}
if (targetNullLen > 0)
@@ -934,6 +955,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
&bitMask,
&targetData,
infoMask,
+ infoMask2,
attrmiss[attnum].am_value,
false);
}
@@ -944,6 +966,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
&bitMask,
&targetData,
infoMask,
+ infoMask2,
(Datum) 0,
true);
}
@@ -1093,6 +1116,7 @@ heap_form_tuple(TupleDesc tupleDescriptor,
(char *) td + hoff,
data_len,
&td->t_infomask,
+ &td->t_infomask2,
(hasnull ? td->t_bits : NULL));
return tuple;
@@ -1415,6 +1439,7 @@ heap_form_minimal_tuple(TupleDesc tupleDescriptor,
(char *) tuple + hoff,
data_len,
&tuple->t_infomask,
+ &tuple->t_infomask2,
(hasnull ? tuple->t_bits : NULL));
return tuple;
diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index 77c742491f..0c73bac69b 100644
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -50,6 +50,7 @@ index_form_tuple(TupleDesc tupleDescriptor,
unsigned short infomask = 0;
bool hasnull = false;
uint16 tupmask = 0;
+ uint16 tupmask2 = 0;
int numberOfAttributes = tupleDescriptor->natts;
#ifdef TOAST_INDEX_HACK
@@ -162,6 +163,7 @@ index_form_tuple(TupleDesc tupleDescriptor,
(char *) tp + hoff,
data_size,
&tupmask,
+ &tupmask2,
(hasnull ? (bits8 *) tp + sizeof(IndexTupleData) : NULL));
#ifdef TOAST_INDEX_HACK
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index 0158950a43..cb344b55aa 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -20,6 +20,7 @@
#include "postgres.h"
#include "access/htup_details.h"
+#include "access/reloptions.h"
#include "access/tupdesc_details.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
@@ -72,6 +73,7 @@ CreateTemplateTupleDesc(int natts)
desc->constr = NULL;
desc->tdtypeid = RECORDOID;
desc->tdtypmod = -1;
+ desc->tdflags = 0;
desc->tdrefcount = -1; /* assume not reference-counted */
return desc;
@@ -94,8 +96,17 @@ CreateTupleDesc(int natts, Form_pg_attribute *attrs)
desc = CreateTemplateTupleDesc(natts);
for (i = 0; i < natts; ++i)
+ {
memcpy(TupleDescAttr(desc, i), attrs[i], ATTRIBUTE_FIXED_PART_SIZE);
+ /*
+ * If even one of attributes is compressed we save information about
+ * it to TupleDesc flags
+ */
+ if (OidIsValid(attrs[i]->attcompression))
+ desc->tdflags |= TD_ATTR_CUSTOM_COMPRESSED;
+ }
+
return desc;
}
@@ -136,6 +147,7 @@ CreateTupleDescCopy(TupleDesc tupdesc)
/* We can copy the tuple type identification, too */
desc->tdtypeid = tupdesc->tdtypeid;
desc->tdtypmod = tupdesc->tdtypmod;
+ desc->tdflags = tupdesc->tdflags;
return desc;
}
@@ -215,6 +227,7 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
/* We can copy the tuple type identification, too */
desc->tdtypeid = tupdesc->tdtypeid;
desc->tdtypmod = tupdesc->tdtypmod;
+ desc->tdflags = tupdesc->tdflags;
return desc;
}
@@ -300,6 +313,7 @@ TupleDescCopyEntry(TupleDesc dst, AttrNumber dstAttno,
dstAtt->atthasdef = false;
dstAtt->atthasmissing = false;
dstAtt->attidentity = '\0';
+ dstAtt->attcompression = InvalidOid;
}
/*
@@ -414,6 +428,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
return false;
if (tupdesc1->tdtypeid != tupdesc2->tdtypeid)
return false;
+ if (tupdesc1->tdflags != tupdesc2->tdflags)
+ return false;
for (i = 0; i < tupdesc1->natts; i++)
{
@@ -464,6 +480,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
return false;
if (attr1->attcollation != attr2->attcollation)
return false;
+ if (attr1->attcompression != attr2->attcompression)
+ return false;
/* attacl, attoptions and attfdwoptions are not even present... */
}
@@ -549,6 +567,7 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
}
else if (tupdesc2->constr != NULL)
return false;
+
return true;
}
@@ -654,6 +673,7 @@ TupleDescInitEntry(TupleDesc desc,
att->attalign = typeForm->typalign;
att->attstorage = typeForm->typstorage;
att->attcollation = typeForm->typcollation;
+ att->attcompression = InvalidOid;
ReleaseSysCache(tuple);
}
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 1ecc16888e..34dd671430 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -70,7 +70,8 @@
static HeapTuple heap_prepare_insert(Relation relation, HeapTuple tup,
- TransactionId xid, CommandId cid, int options);
+ TransactionId xid, CommandId cid, int options,
+ BulkInsertState bistate);
static XLogRecPtr log_heap_update(Relation reln, Buffer oldbuf,
Buffer newbuf, HeapTuple oldtup,
HeapTuple newtup, HeapTuple old_key_tup,
@@ -1846,13 +1847,14 @@ UpdateXmaxHintBits(HeapTupleHeader tuple, Buffer buffer, TransactionId xid)
* GetBulkInsertState - prepare status object for a bulk insert
*/
BulkInsertState
-GetBulkInsertState(void)
+GetBulkInsertState(HTAB *preserved_am_info)
{
BulkInsertState bistate;
bistate = (BulkInsertState) palloc(sizeof(BulkInsertStateData));
bistate->strategy = GetAccessStrategy(BAS_BULKWRITE);
bistate->current_buf = InvalidBuffer;
+ bistate->preserved_am_info = preserved_am_info;
return bistate;
}
@@ -1942,7 +1944,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid,
* Note: below this point, heaptup is the data we actually intend to store
* into the relation; tup is the caller's original untoasted data.
*/
- heaptup = heap_prepare_insert(relation, tup, xid, cid, options);
+ heaptup = heap_prepare_insert(relation, tup, xid, cid, options, bistate);
/*
* Find buffer to insert this tuple into. If the page is all visible,
@@ -2109,7 +2111,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid,
*/
static HeapTuple
heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
- CommandId cid, int options)
+ CommandId cid, int options, BulkInsertState bistate)
{
/*
* Parallel operations are required to be strictly read-only in a parallel
@@ -2147,8 +2149,11 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
return tup;
}
else if (HeapTupleHasExternal(tup)
+ || RelationGetDescr(relation)->tdflags & TD_ATTR_CUSTOM_COMPRESSED
+ || HeapTupleHasCustomCompressed(tup)
|| tup->t_len > TOAST_TUPLE_THRESHOLD)
- return toast_insert_or_update(relation, tup, NULL, options, NULL);
+ return toast_insert_or_update(relation, tup, NULL, options,
+ bistate ? bistate->preserved_am_info : NULL);
else
return tup;
}
@@ -2190,7 +2195,7 @@ heap_multi_insert(Relation relation, HeapTuple *tuples, int ntuples,
heaptuples = palloc(ntuples * sizeof(HeapTuple));
for (i = 0; i < ntuples; i++)
heaptuples[i] = heap_prepare_insert(relation, tuples[i],
- xid, cid, options);
+ xid, cid, options, bistate);
/*
* We're about to do the actual inserts -- but check for conflict first,
@@ -3467,6 +3472,8 @@ l2:
else
need_toast = (HeapTupleHasExternal(&oldtup) ||
HeapTupleHasExternal(newtup) ||
+ RelationGetDescr(relation)->tdflags & TD_ATTR_CUSTOM_COMPRESSED ||
+ HeapTupleHasCustomCompressed(newtup) ||
newtup->t_len > TOAST_TUPLE_THRESHOLD);
pagefree = PageGetHeapFreeSpace(page);
diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c
index 6082ee9a38..176416a943 100644
--- a/src/backend/access/heap/tuptoaster.c
+++ b/src/backend/access/heap/tuptoaster.c
@@ -1190,6 +1190,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
(char *) new_data + new_header_len,
new_data_len,
&(new_data->t_infomask),
+ &(new_data->t_infomask2),
has_nulls ? new_data->t_bits : NULL);
}
else
@@ -1411,6 +1412,7 @@ toast_flatten_tuple_to_datum(HeapTupleHeader tup,
(char *) new_data + new_header_len,
new_data_len,
&(new_data->t_infomask),
+ &(new_data->t_infomask2),
has_nulls ? new_data->t_bits : NULL);
/*
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 218a6e01cb..acf00191b8 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -2662,7 +2662,7 @@ CopyFrom(CopyState cstate)
values = (Datum *) palloc(tupDesc->natts * sizeof(Datum));
nulls = (bool *) palloc(tupDesc->natts * sizeof(bool));
- bistate = GetBulkInsertState();
+ bistate = GetBulkInsertState(NULL);
econtext = GetPerTupleExprContext(estate);
/* Set up callback to identify error line number */
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 36e3d44aad..8a52a53472 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -559,7 +559,7 @@ intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
*/
myState->hi_options = HEAP_INSERT_SKIP_FSM |
(XLogIsNeeded() ? 0 : HEAP_INSERT_SKIP_WAL);
- myState->bistate = GetBulkInsertState();
+ myState->bistate = GetBulkInsertState(NULL);
/* Not using WAL requires smgr_targblock be initially invalid */
Assert(RelationGetTargetBlock(intoRelationDesc) == InvalidBlockNumber);
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 5a47be4b33..982a287e8c 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -464,7 +464,7 @@ transientrel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
myState->hi_options = HEAP_INSERT_SKIP_FSM | HEAP_INSERT_FROZEN;
if (!XLogIsNeeded())
myState->hi_options |= HEAP_INSERT_SKIP_WAL;
- myState->bistate = GetBulkInsertState();
+ myState->bistate = GetBulkInsertState(NULL);
/* Not using WAL requires smgr_targblock be initially invalid */
Assert(RelationGetTargetBlock(transientrel) == InvalidBlockNumber);
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 90361f2a59..185c9650c7 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -165,6 +165,9 @@ typedef struct AlteredTableInfo
List *constraints; /* List of NewConstraint */
List *newvals; /* List of NewColumnValue */
bool verify_new_notnull; /* T if we should recheck NOT NULL */
+ bool new_notnull; /* T if we added new NOT NULL constraints */
+ HTAB *preservedAmInfo; /* Hash table for preserved compression
+ * methods */
int rewrite; /* Reason for forced rewrite, if any */
Oid newTableSpace; /* new tablespace; 0 means no change */
bool chgPersistence; /* T if SET LOGGED/UNLOGGED is used */
@@ -4727,7 +4730,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
if (newrel)
{
mycid = GetCurrentCommandId(true);
- bistate = GetBulkInsertState();
+ bistate = GetBulkInsertState(tab->preservedAmInfo);
hi_options = HEAP_INSERT_SKIP_FSM;
if (!XLogIsNeeded())
@@ -5016,6 +5019,24 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
FreeExecutorState(estate);
+ /* Remove old compression options */
+ if (tab->rewrite & AT_REWRITE_ALTER_COMPRESSION)
+ {
+ AttrCmPreservedInfo *pinfo;
+ HASH_SEQ_STATUS status;
+
+ Assert(tab->preservedAmInfo);
+ hash_seq_init(&status, tab->preservedAmInfo);
+ while ((pinfo = (AttrCmPreservedInfo *) hash_seq_search(&status)) != NULL)
+ {
+ CleanupAttributeCompression(tab->relid, pinfo->attnum,
+ pinfo->preserved_amoids);
+ list_free(pinfo->preserved_amoids);
+ }
+
+ hash_destroy(tab->preservedAmInfo);
+ }
+
table_close(oldrel, NoLock);
if (newrel)
{
@@ -9505,6 +9526,45 @@ createForeignKeyTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint,
CommandCounterIncrement();
}
+/*
+ * Initialize hash table used to keep rewrite rules for
+ * compression changes in ALTER commands.
+ */
+static void
+setupCompressionRewriteRules(AlteredTableInfo *tab, const char *column,
+ AttrNumber attnum, List *preserved_amoids)
+{
+ bool found;
+ AttrCmPreservedInfo *pinfo;
+
+ Assert(!IsBinaryUpgrade);
+ tab->rewrite |= AT_REWRITE_ALTER_COMPRESSION;
+
+ /* initialize hash for oids */
+ if (tab->preservedAmInfo == NULL)
+ {
+ HASHCTL ctl;
+
+ MemSet(&ctl, 0, sizeof(ctl));
+ ctl.keysize = sizeof(AttrNumber);
+ ctl.entrysize = sizeof(AttrCmPreservedInfo);
+ tab->preservedAmInfo =
+ hash_create("preserved access methods cache", 10, &ctl,
+ HASH_ELEM | HASH_BLOBS);
+ }
+ pinfo = (AttrCmPreservedInfo *) hash_search(tab->preservedAmInfo,
+ &attnum, HASH_ENTER, &found);
+
+ if (found)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter compression of column \"%s\" twice", column),
+ errhint("Remove one of statements from the command.")));
+
+ pinfo->attnum = attnum;
+ pinfo->preserved_amoids = preserved_amoids;
+}
+
/*
* ALTER TABLE DROP CONSTRAINT
*
@@ -10496,7 +10556,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
{
/* Set up rewrite of table */
attTup->attcompression = InvalidOid;
- /* TODO: call the rewrite function here */
+ setupCompressionRewriteRules(tab, colName, attOldTup->attnum, NIL);
}
else if (OidIsValid(attTup->attcompression))
{
@@ -10504,7 +10564,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
ColumnCompression *compression = MakeColumnCompression(attTup->attcompression);
if (!IsBuiltinCompression(attTup->attcompression))
- /* TODO: call the rewrite function here */;
+ setupCompressionRewriteRules(tab, colName, attOldTup->attnum, NIL);
attTup->attcompression = CreateAttributeCompression(attTup, compression, NULL, NULL);
}
@@ -13620,7 +13680,8 @@ ATExecSetCompression(AlteredTableInfo *tab,
* toast_insert_or_update
*/
if (need_rewrite)
- /* TODO: set up rewrite rules here */;
+ setupCompressionRewriteRules(tab, column, atttableform->attnum,
+ preserved_amoids);
atttableform->attcompression = acoid;
CatalogTupleUpdate(attrel, &atttuple->t_self, atttuple);
diff --git a/src/backend/utils/adt/expandedrecord.c b/src/backend/utils/adt/expandedrecord.c
index 9971abd71f..71fffc53b8 100644
--- a/src/backend/utils/adt/expandedrecord.c
+++ b/src/backend/utils/adt/expandedrecord.c
@@ -808,6 +808,7 @@ ER_flatten_into(ExpandedObjectHeader *eohptr,
(char *) tuphdr + erh->hoff,
erh->data_len,
&tuphdr->t_infomask,
+ &tuphdr->t_infomask2,
(erh->hasnull ? tuphdr->t_bits : NULL));
}
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index eba77491fd..6fa67242ef 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -569,6 +569,10 @@ RelationBuildTupleDesc(Relation relation)
ndef++;
}
+ /* mark tupledesc as it contains attributes with custom compression */
+ if (attp->attcompression)
+ relation->rd_att->tdflags |= TD_ATTR_CUSTOM_COMPRESSED;
+
/* Likewise for a missing value */
if (attp->atthasmissing)
{
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 1b6607fe90..aa54b52476 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -25,6 +25,7 @@
#include "storage/lockdefs.h"
#include "utils/relcache.h"
#include "utils/snapshot.h"
+#include "utils/hsearch.h"
/* "options" flag bits for heap_insert */
@@ -162,7 +163,7 @@ extern void heap_get_latest_tid(Relation relation, Snapshot snapshot,
ItemPointer tid);
extern void setLastTid(const ItemPointer tid);
-extern BulkInsertState GetBulkInsertState(void);
+extern BulkInsertState GetBulkInsertState(HTAB *);
extern void FreeBulkInsertState(BulkInsertState);
extern void ReleaseBulkInsertStatePin(BulkInsertState bistate);
diff --git a/src/include/access/hio.h b/src/include/access/hio.h
index cec087cb1a..84c736cea2 100644
--- a/src/include/access/hio.h
+++ b/src/include/access/hio.h
@@ -31,6 +31,8 @@ typedef struct BulkInsertStateData
{
BufferAccessStrategy strategy; /* our BULKWRITE strategy object */
Buffer current_buf; /* current insertion target page */
+ HTAB *preserved_am_info; /* hash table with preserved compression
+ * methods for attributes */
} BulkInsertStateData;
diff --git a/src/include/access/htup_details.h b/src/include/access/htup_details.h
index 6d51f9062b..1ab905a131 100644
--- a/src/include/access/htup_details.h
+++ b/src/include/access/htup_details.h
@@ -274,7 +274,9 @@ struct HeapTupleHeaderData
* information stored in t_infomask2:
*/
#define HEAP_NATTS_MASK 0x07FF /* 11 bits for number of attributes */
-/* bits 0x1800 are available */
+/* bit 0x800 is available */
+#define HEAP_HASCUSTOMCOMPRESSED 0x1000 /* tuple contains custom compressed
+ * varlena(s) */
#define HEAP_KEYS_UPDATED 0x2000 /* tuple was updated and key cols
* modified, or tuple deleted */
#define HEAP_HOT_UPDATED 0x4000 /* tuple was HOT-updated */
@@ -673,6 +675,9 @@ struct MinimalTupleData
#define HeapTupleHasExternal(tuple) \
(((tuple)->t_data->t_infomask & HEAP_HASEXTERNAL) != 0)
+#define HeapTupleHasCustomCompressed(tuple) \
+ (((tuple)->t_data->t_infomask2 & HEAP_HASCUSTOMCOMPRESSED) != 0)
+
#define HeapTupleIsHotUpdated(tuple) \
HeapTupleHeaderIsHotUpdated((tuple)->t_data)
@@ -779,7 +784,7 @@ extern Size heap_compute_data_size(TupleDesc tupleDesc,
extern void heap_fill_tuple(TupleDesc tupleDesc,
Datum *values, bool *isnull,
char *data, Size data_size,
- uint16 *infomask, bits8 *bit);
+ uint16 *infomask, uint16 *infomask2, bits8 *bit);
extern bool heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc);
extern Datum nocachegetattr(HeapTuple tup, int attnum,
TupleDesc att);
diff --git a/src/include/access/tupdesc.h b/src/include/access/tupdesc.h
index 66d1b2fc40..c878a0636a 100644
--- a/src/include/access/tupdesc.h
+++ b/src/include/access/tupdesc.h
@@ -14,7 +14,9 @@
#ifndef TUPDESC_H
#define TUPDESC_H
+#include "postgres.h"
#include "access/attnum.h"
+#include "access/cmapi.h"
#include "catalog/pg_attribute.h"
#include "nodes/pg_list.h"
@@ -44,6 +46,10 @@ typedef struct TupleConstr
bool has_not_null;
} TupleConstr;
+/* tupledesc flags */
+#define TD_ATTR_CUSTOM_COMPRESSED 0x01 /* is TupleDesc contain attributes
+ * with custom compression? */
+
/*
* This struct is passed around within the backend to describe the structure
* of tuples. For tuples coming from on-disk relations, the information is
@@ -80,6 +86,7 @@ typedef struct TupleDescData
int natts; /* number of attributes in the tuple */
Oid tdtypeid; /* composite type ID for tuple type */
int32 tdtypmod; /* typmod for tuple type */
+ char tdflags; /* tuple additional flags */
int tdrefcount; /* reference count, or -1 if not counting */
TupleConstr *constr; /* constraints, or NULL if none */
/* attrs[N] is the description of Attribute Number N+1 */
diff --git a/src/include/access/tuptoaster.h b/src/include/access/tuptoaster.h
index fad14bad85..aaf3b155dc 100644
--- a/src/include/access/tuptoaster.h
+++ b/src/include/access/tuptoaster.h
@@ -13,7 +13,6 @@
#ifndef TUPTOASTER_H
#define TUPTOASTER_H
-#include "access/cmapi.h"
#include "access/htup_details.h"
#include "storage/lockdefs.h"
#include "utils/relcache.h"
diff --git a/src/include/commands/event_trigger.h b/src/include/commands/event_trigger.h
index 0b8c7cca21..9252ad3d3a 100644
--- a/src/include/commands/event_trigger.h
+++ b/src/include/commands/event_trigger.h
@@ -31,6 +31,7 @@ typedef struct EventTriggerData
#define AT_REWRITE_ALTER_PERSISTENCE 0x01
#define AT_REWRITE_DEFAULT_VAL 0x02
#define AT_REWRITE_COLUMN_REWRITE 0x04
+#define AT_REWRITE_ALTER_COMPRESSION 0x08
/*
* EventTriggerData is the node type that is passed as fmgr "context" info
--
2.21.0
--MP_//XvyHCr_hJMvh/tp2R3=uJa
Content-Type: text/x-patch
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
filename=0004-Add-pglz-compression-method-v22.patch
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops
@ 2019-03-07 20:49 Nikita Glukhov <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Nikita Glukhov @ 2019-03-07 20:49 UTC (permalink / raw)
---
doc/src/sgml/spgist.sgml | 1 +
src/include/catalog/pg_amop.dat | 4 ++
src/test/regress/expected/box.out | 82 +++++++++++++++++++++++++-----
src/test/regress/expected/sanity_check.out | 2 +
src/test/regress/sql/box.sql | 70 ++++++++++++++++++++-----
5 files changed, 135 insertions(+), 24 deletions(-)
diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml
index 7cf9d0e..9070914 100644
--- a/doc/src/sgml/spgist.sgml
+++ b/doc/src/sgml/spgist.sgml
@@ -139,6 +139,7 @@
<literal>|&></literal>
</entry>
<entry>
+ <literal><-></literal>
</entry>
</row>
<row>
diff --git a/src/include/catalog/pg_amop.dat b/src/include/catalog/pg_amop.dat
index ebc38ae..232557e 100644
--- a/src/include/catalog/pg_amop.dat
+++ b/src/include/catalog/pg_amop.dat
@@ -1546,6 +1546,10 @@
amopstrategy => '11', amopopr => '|>>(box,box)', amopmethod => 'spgist' },
{ amopfamily => 'spgist/box_ops', amoplefttype => 'box', amoprighttype => 'box',
amopstrategy => '12', amopopr => '|&>(box,box)', amopmethod => 'spgist' },
+{ amopfamily => 'spgist/box_ops', amoplefttype => 'box',
+ amoprighttype => 'point', amopstrategy => '15', amoppurpose => 'o',
+ amopopr => '<->(box,point)', amopmethod => 'spgist',
+ amopsortfamily => 'btree/float_ops' },
# SP-GiST poly_ops (supports polygons)
{ amopfamily => 'spgist/poly_ops', amoplefttype => 'polygon',
diff --git a/src/test/regress/expected/box.out b/src/test/regress/expected/box.out
index 998b522..4d0f169 100644
--- a/src/test/regress/expected/box.out
+++ b/src/test/regress/expected/box.out
@@ -480,23 +480,33 @@ DROP INDEX box_spgist;
--
-- Test the SP-GiST index on the larger volume of data
--
-CREATE TABLE quad_box_tbl (b box);
+CREATE TABLE quad_box_tbl (id int, b box);
INSERT INTO quad_box_tbl
- SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
- FROM generate_series(1, 100) x,
- generate_series(1, 100) y;
+ SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
+ FROM generate_series(1, 100) x,
+ generate_series(1, 100) y;
-- insert repeating data to test allTheSame
INSERT INTO quad_box_tbl
- SELECT '((200, 300),(210, 310))'
- FROM generate_series(1, 1000);
+ SELECT i, '((200, 300),(210, 310))'
+ FROM generate_series(10001, 11000) AS i;
INSERT INTO quad_box_tbl
- VALUES
- (NULL),
- (NULL),
- ('((-infinity,-infinity),(infinity,infinity))'),
- ('((-infinity,100),(-infinity,500))'),
- ('((-infinity,-infinity),(700,infinity))');
+VALUES
+ (11001, NULL),
+ (11002, NULL),
+ (11003, '((-infinity,-infinity),(infinity,infinity))'),
+ (11004, '((-infinity,100),(-infinity,500))'),
+ (11005, '((-infinity,-infinity),(700,infinity))');
CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b);
+-- get reference results for ORDER BY distance from seq scan
+SET enable_seqscan = ON;
+SET enable_indexscan = OFF;
+SET enable_bitmapscan = OFF;
+CREATE TABLE quad_box_tbl_ord_seq1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+CREATE TABLE quad_box_tbl_ord_seq2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
SET enable_bitmapscan = ON;
@@ -578,6 +588,54 @@ SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))';
1
(1 row)
+-- test ORDER BY distance
+SET enable_indexscan = ON;
+SET enable_bitmapscan = OFF;
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+ QUERY PLAN
+---------------------------------------------------------
+ WindowAgg
+ -> Index Scan using quad_box_tbl_idx on quad_box_tbl
+ Order By: (b <-> '(123,456)'::point)
+(3 rows)
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+SELECT *
+FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+ n | dist | id | n | dist | id
+---+------+----+---+------+----
+(0 rows)
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+ QUERY PLAN
+---------------------------------------------------------
+ WindowAgg
+ -> Index Scan using quad_box_tbl_idx on quad_box_tbl
+ Index Cond: (b <@ '(500,600),(200,300)'::box)
+ Order By: (b <-> '(123,456)'::point)
+(4 rows)
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+SELECT *
+FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+ n | dist | id | n | dist | id
+---+------+----+---+------+----
+(0 rows)
+
RESET enable_seqscan;
RESET enable_indexscan;
RESET enable_bitmapscan;
diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out
index 8ff0da1..d6e75ff 100644
--- a/src/test/regress/expected/sanity_check.out
+++ b/src/test/regress/expected/sanity_check.out
@@ -165,6 +165,8 @@ pg_user_mapping|t
point_tbl|t
polygon_tbl|t
quad_box_tbl|t
+quad_box_tbl_ord_seq1|f
+quad_box_tbl_ord_seq2|f
quad_point_tbl|t
quad_poly_tbl|t
radix_text_tbl|t
diff --git a/src/test/regress/sql/box.sql b/src/test/regress/sql/box.sql
index 6710fc9..cd3e002 100644
--- a/src/test/regress/sql/box.sql
+++ b/src/test/regress/sql/box.sql
@@ -192,28 +192,41 @@ DROP INDEX box_spgist;
--
-- Test the SP-GiST index on the larger volume of data
--
-CREATE TABLE quad_box_tbl (b box);
+CREATE TABLE quad_box_tbl (id int, b box);
INSERT INTO quad_box_tbl
- SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
- FROM generate_series(1, 100) x,
- generate_series(1, 100) y;
+ SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
+ FROM generate_series(1, 100) x,
+ generate_series(1, 100) y;
-- insert repeating data to test allTheSame
INSERT INTO quad_box_tbl
- SELECT '((200, 300),(210, 310))'
- FROM generate_series(1, 1000);
+ SELECT i, '((200, 300),(210, 310))'
+ FROM generate_series(10001, 11000) AS i;
INSERT INTO quad_box_tbl
- VALUES
- (NULL),
- (NULL),
- ('((-infinity,-infinity),(infinity,infinity))'),
- ('((-infinity,100),(-infinity,500))'),
- ('((-infinity,-infinity),(700,infinity))');
+VALUES
+ (11001, NULL),
+ (11002, NULL),
+ (11003, '((-infinity,-infinity),(infinity,infinity))'),
+ (11004, '((-infinity,100),(-infinity,500))'),
+ (11005, '((-infinity,-infinity),(700,infinity))');
CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b);
+-- get reference results for ORDER BY distance from seq scan
+SET enable_seqscan = ON;
+SET enable_indexscan = OFF;
+SET enable_bitmapscan = OFF;
+
+CREATE TABLE quad_box_tbl_ord_seq1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+CREATE TABLE quad_box_tbl_ord_seq2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
SET enable_bitmapscan = ON;
@@ -232,6 +245,39 @@ SELECT count(*) FROM quad_box_tbl WHERE b @> box '((201,301),(202,303))';
SELECT count(*) FROM quad_box_tbl WHERE b <@ box '((100,200),(300,500))';
SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))';
+-- test ORDER BY distance
+SET enable_indexscan = ON;
+SET enable_bitmapscan = OFF;
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+SELECT *
+FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
+SELECT *
+FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+
RESET enable_seqscan;
RESET enable_indexscan;
RESET enable_bitmapscan;
--
2.7.4
--------------07EE9595454874974EAD75E7--
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops
@ 2019-03-07 20:49 Nikita Glukhov <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Nikita Glukhov @ 2019-03-07 20:49 UTC (permalink / raw)
---
doc/src/sgml/spgist.sgml | 1 +
src/include/catalog/pg_amop.dat | 4 ++
src/test/regress/expected/box.out | 82 +++++++++++++++++++++++++-----
src/test/regress/expected/sanity_check.out | 2 +
src/test/regress/sql/box.sql | 70 ++++++++++++++++++++-----
5 files changed, 135 insertions(+), 24 deletions(-)
diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml
index a816856..81ddf5d 100644
--- a/doc/src/sgml/spgist.sgml
+++ b/doc/src/sgml/spgist.sgml
@@ -139,6 +139,7 @@
<literal>|&></literal>
</entry>
<entry>
+ <literal><-></literal>
</entry>
</row>
<row>
diff --git a/src/include/catalog/pg_amop.dat b/src/include/catalog/pg_amop.dat
index ebc38ae..232557e 100644
--- a/src/include/catalog/pg_amop.dat
+++ b/src/include/catalog/pg_amop.dat
@@ -1546,6 +1546,10 @@
amopstrategy => '11', amopopr => '|>>(box,box)', amopmethod => 'spgist' },
{ amopfamily => 'spgist/box_ops', amoplefttype => 'box', amoprighttype => 'box',
amopstrategy => '12', amopopr => '|&>(box,box)', amopmethod => 'spgist' },
+{ amopfamily => 'spgist/box_ops', amoplefttype => 'box',
+ amoprighttype => 'point', amopstrategy => '15', amoppurpose => 'o',
+ amopopr => '<->(box,point)', amopmethod => 'spgist',
+ amopsortfamily => 'btree/float_ops' },
# SP-GiST poly_ops (supports polygons)
{ amopfamily => 'spgist/poly_ops', amoplefttype => 'polygon',
diff --git a/src/test/regress/expected/box.out b/src/test/regress/expected/box.out
index 998b522..4d0f169 100644
--- a/src/test/regress/expected/box.out
+++ b/src/test/regress/expected/box.out
@@ -480,23 +480,33 @@ DROP INDEX box_spgist;
--
-- Test the SP-GiST index on the larger volume of data
--
-CREATE TABLE quad_box_tbl (b box);
+CREATE TABLE quad_box_tbl (id int, b box);
INSERT INTO quad_box_tbl
- SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
- FROM generate_series(1, 100) x,
- generate_series(1, 100) y;
+ SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
+ FROM generate_series(1, 100) x,
+ generate_series(1, 100) y;
-- insert repeating data to test allTheSame
INSERT INTO quad_box_tbl
- SELECT '((200, 300),(210, 310))'
- FROM generate_series(1, 1000);
+ SELECT i, '((200, 300),(210, 310))'
+ FROM generate_series(10001, 11000) AS i;
INSERT INTO quad_box_tbl
- VALUES
- (NULL),
- (NULL),
- ('((-infinity,-infinity),(infinity,infinity))'),
- ('((-infinity,100),(-infinity,500))'),
- ('((-infinity,-infinity),(700,infinity))');
+VALUES
+ (11001, NULL),
+ (11002, NULL),
+ (11003, '((-infinity,-infinity),(infinity,infinity))'),
+ (11004, '((-infinity,100),(-infinity,500))'),
+ (11005, '((-infinity,-infinity),(700,infinity))');
CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b);
+-- get reference results for ORDER BY distance from seq scan
+SET enable_seqscan = ON;
+SET enable_indexscan = OFF;
+SET enable_bitmapscan = OFF;
+CREATE TABLE quad_box_tbl_ord_seq1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+CREATE TABLE quad_box_tbl_ord_seq2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
SET enable_bitmapscan = ON;
@@ -578,6 +588,54 @@ SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))';
1
(1 row)
+-- test ORDER BY distance
+SET enable_indexscan = ON;
+SET enable_bitmapscan = OFF;
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+ QUERY PLAN
+---------------------------------------------------------
+ WindowAgg
+ -> Index Scan using quad_box_tbl_idx on quad_box_tbl
+ Order By: (b <-> '(123,456)'::point)
+(3 rows)
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+SELECT *
+FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+ n | dist | id | n | dist | id
+---+------+----+---+------+----
+(0 rows)
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+ QUERY PLAN
+---------------------------------------------------------
+ WindowAgg
+ -> Index Scan using quad_box_tbl_idx on quad_box_tbl
+ Index Cond: (b <@ '(500,600),(200,300)'::box)
+ Order By: (b <-> '(123,456)'::point)
+(4 rows)
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+SELECT *
+FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+ n | dist | id | n | dist | id
+---+------+----+---+------+----
+(0 rows)
+
RESET enable_seqscan;
RESET enable_indexscan;
RESET enable_bitmapscan;
diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out
index 8ff0da1..d6e75ff 100644
--- a/src/test/regress/expected/sanity_check.out
+++ b/src/test/regress/expected/sanity_check.out
@@ -165,6 +165,8 @@ pg_user_mapping|t
point_tbl|t
polygon_tbl|t
quad_box_tbl|t
+quad_box_tbl_ord_seq1|f
+quad_box_tbl_ord_seq2|f
quad_point_tbl|t
quad_poly_tbl|t
radix_text_tbl|t
diff --git a/src/test/regress/sql/box.sql b/src/test/regress/sql/box.sql
index 6710fc9..cd3e002 100644
--- a/src/test/regress/sql/box.sql
+++ b/src/test/regress/sql/box.sql
@@ -192,28 +192,41 @@ DROP INDEX box_spgist;
--
-- Test the SP-GiST index on the larger volume of data
--
-CREATE TABLE quad_box_tbl (b box);
+CREATE TABLE quad_box_tbl (id int, b box);
INSERT INTO quad_box_tbl
- SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
- FROM generate_series(1, 100) x,
- generate_series(1, 100) y;
+ SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
+ FROM generate_series(1, 100) x,
+ generate_series(1, 100) y;
-- insert repeating data to test allTheSame
INSERT INTO quad_box_tbl
- SELECT '((200, 300),(210, 310))'
- FROM generate_series(1, 1000);
+ SELECT i, '((200, 300),(210, 310))'
+ FROM generate_series(10001, 11000) AS i;
INSERT INTO quad_box_tbl
- VALUES
- (NULL),
- (NULL),
- ('((-infinity,-infinity),(infinity,infinity))'),
- ('((-infinity,100),(-infinity,500))'),
- ('((-infinity,-infinity),(700,infinity))');
+VALUES
+ (11001, NULL),
+ (11002, NULL),
+ (11003, '((-infinity,-infinity),(infinity,infinity))'),
+ (11004, '((-infinity,100),(-infinity,500))'),
+ (11005, '((-infinity,-infinity),(700,infinity))');
CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b);
+-- get reference results for ORDER BY distance from seq scan
+SET enable_seqscan = ON;
+SET enable_indexscan = OFF;
+SET enable_bitmapscan = OFF;
+
+CREATE TABLE quad_box_tbl_ord_seq1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+CREATE TABLE quad_box_tbl_ord_seq2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
SET enable_bitmapscan = ON;
@@ -232,6 +245,39 @@ SELECT count(*) FROM quad_box_tbl WHERE b @> box '((201,301),(202,303))';
SELECT count(*) FROM quad_box_tbl WHERE b <@ box '((100,200),(300,500))';
SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))';
+-- test ORDER BY distance
+SET enable_indexscan = ON;
+SET enable_bitmapscan = OFF;
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+SELECT *
+FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
+SELECT *
+FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+
RESET enable_seqscan;
RESET enable_indexscan;
RESET enable_bitmapscan;
--
2.7.4
--------------C466D744B1EAB9FA85D22553--
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops
@ 2019-03-07 20:49 Nikita Glukhov <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Nikita Glukhov @ 2019-03-07 20:49 UTC (permalink / raw)
---
doc/src/sgml/spgist.sgml | 1 +
src/include/catalog/pg_amop.dat | 4 ++
src/test/regress/expected/box.out | 82 +++++++++++++++++++++++++-----
src/test/regress/expected/sanity_check.out | 2 +
src/test/regress/sql/box.sql | 70 ++++++++++++++++++++-----
5 files changed, 135 insertions(+), 24 deletions(-)
diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml
index 126d1f6..8bc8ad7 100644
--- a/doc/src/sgml/spgist.sgml
+++ b/doc/src/sgml/spgist.sgml
@@ -139,6 +139,7 @@
<literal>|&></literal>
</entry>
<entry>
+ <literal><-></literal>
</entry>
</row>
<row>
diff --git a/src/include/catalog/pg_amop.dat b/src/include/catalog/pg_amop.dat
index 8e74f86..797223d 100644
--- a/src/include/catalog/pg_amop.dat
+++ b/src/include/catalog/pg_amop.dat
@@ -1534,6 +1534,10 @@
amopstrategy => '11', amopopr => '|>>(box,box)', amopmethod => 'spgist' },
{ amopfamily => 'spgist/box_ops', amoplefttype => 'box', amoprighttype => 'box',
amopstrategy => '12', amopopr => '|&>(box,box)', amopmethod => 'spgist' },
+{ amopfamily => 'spgist/box_ops', amoplefttype => 'box',
+ amoprighttype => 'point', amopstrategy => '15', amoppurpose => 'o',
+ amopopr => '<->(box,point)', amopmethod => 'spgist',
+ amopsortfamily => 'btree/float_ops' },
# SP-GiST poly_ops (supports polygons)
{ amopfamily => 'spgist/poly_ops', amoplefttype => 'polygon',
diff --git a/src/test/regress/expected/box.out b/src/test/regress/expected/box.out
index 998b522..4d0f169 100644
--- a/src/test/regress/expected/box.out
+++ b/src/test/regress/expected/box.out
@@ -480,23 +480,33 @@ DROP INDEX box_spgist;
--
-- Test the SP-GiST index on the larger volume of data
--
-CREATE TABLE quad_box_tbl (b box);
+CREATE TABLE quad_box_tbl (id int, b box);
INSERT INTO quad_box_tbl
- SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
- FROM generate_series(1, 100) x,
- generate_series(1, 100) y;
+ SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
+ FROM generate_series(1, 100) x,
+ generate_series(1, 100) y;
-- insert repeating data to test allTheSame
INSERT INTO quad_box_tbl
- SELECT '((200, 300),(210, 310))'
- FROM generate_series(1, 1000);
+ SELECT i, '((200, 300),(210, 310))'
+ FROM generate_series(10001, 11000) AS i;
INSERT INTO quad_box_tbl
- VALUES
- (NULL),
- (NULL),
- ('((-infinity,-infinity),(infinity,infinity))'),
- ('((-infinity,100),(-infinity,500))'),
- ('((-infinity,-infinity),(700,infinity))');
+VALUES
+ (11001, NULL),
+ (11002, NULL),
+ (11003, '((-infinity,-infinity),(infinity,infinity))'),
+ (11004, '((-infinity,100),(-infinity,500))'),
+ (11005, '((-infinity,-infinity),(700,infinity))');
CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b);
+-- get reference results for ORDER BY distance from seq scan
+SET enable_seqscan = ON;
+SET enable_indexscan = OFF;
+SET enable_bitmapscan = OFF;
+CREATE TABLE quad_box_tbl_ord_seq1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+CREATE TABLE quad_box_tbl_ord_seq2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
SET enable_bitmapscan = ON;
@@ -578,6 +588,54 @@ SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))';
1
(1 row)
+-- test ORDER BY distance
+SET enable_indexscan = ON;
+SET enable_bitmapscan = OFF;
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+ QUERY PLAN
+---------------------------------------------------------
+ WindowAgg
+ -> Index Scan using quad_box_tbl_idx on quad_box_tbl
+ Order By: (b <-> '(123,456)'::point)
+(3 rows)
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+SELECT *
+FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+ n | dist | id | n | dist | id
+---+------+----+---+------+----
+(0 rows)
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+ QUERY PLAN
+---------------------------------------------------------
+ WindowAgg
+ -> Index Scan using quad_box_tbl_idx on quad_box_tbl
+ Index Cond: (b <@ '(500,600),(200,300)'::box)
+ Order By: (b <-> '(123,456)'::point)
+(4 rows)
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+SELECT *
+FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+ n | dist | id | n | dist | id
+---+------+----+---+------+----
+(0 rows)
+
RESET enable_seqscan;
RESET enable_indexscan;
RESET enable_bitmapscan;
diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out
index aaaa488..850de0c 100644
--- a/src/test/regress/expected/sanity_check.out
+++ b/src/test/regress/expected/sanity_check.out
@@ -167,6 +167,8 @@ pg_user_mapping|t
point_tbl|t
polygon_tbl|t
quad_box_tbl|t
+quad_box_tbl_ord_seq1|f
+quad_box_tbl_ord_seq2|f
quad_point_tbl|t
quad_poly_tbl|t
quad_poly_tbl_ord_seq1|f
diff --git a/src/test/regress/sql/box.sql b/src/test/regress/sql/box.sql
index 6710fc9..cd3e002 100644
--- a/src/test/regress/sql/box.sql
+++ b/src/test/regress/sql/box.sql
@@ -192,28 +192,41 @@ DROP INDEX box_spgist;
--
-- Test the SP-GiST index on the larger volume of data
--
-CREATE TABLE quad_box_tbl (b box);
+CREATE TABLE quad_box_tbl (id int, b box);
INSERT INTO quad_box_tbl
- SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
- FROM generate_series(1, 100) x,
- generate_series(1, 100) y;
+ SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5))
+ FROM generate_series(1, 100) x,
+ generate_series(1, 100) y;
-- insert repeating data to test allTheSame
INSERT INTO quad_box_tbl
- SELECT '((200, 300),(210, 310))'
- FROM generate_series(1, 1000);
+ SELECT i, '((200, 300),(210, 310))'
+ FROM generate_series(10001, 11000) AS i;
INSERT INTO quad_box_tbl
- VALUES
- (NULL),
- (NULL),
- ('((-infinity,-infinity),(infinity,infinity))'),
- ('((-infinity,100),(-infinity,500))'),
- ('((-infinity,-infinity),(700,infinity))');
+VALUES
+ (11001, NULL),
+ (11002, NULL),
+ (11003, '((-infinity,-infinity),(infinity,infinity))'),
+ (11004, '((-infinity,100),(-infinity,500))'),
+ (11005, '((-infinity,-infinity),(700,infinity))');
CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b);
+-- get reference results for ORDER BY distance from seq scan
+SET enable_seqscan = ON;
+SET enable_indexscan = OFF;
+SET enable_bitmapscan = OFF;
+
+CREATE TABLE quad_box_tbl_ord_seq1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+CREATE TABLE quad_box_tbl_ord_seq2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
SET enable_bitmapscan = ON;
@@ -232,6 +245,39 @@ SELECT count(*) FROM quad_box_tbl WHERE b @> box '((201,301),(202,303))';
SELECT count(*) FROM quad_box_tbl WHERE b <@ box '((100,200),(300,500))';
SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))';
+-- test ORDER BY distance
+SET enable_indexscan = ON;
+SET enable_bitmapscan = OFF;
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl;
+
+SELECT *
+FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+
+
+EXPLAIN (COSTS OFF)
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
+CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS
+SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id
+FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))';
+
+SELECT *
+FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx
+ ON seq.n = idx.n AND seq.id = idx.id AND
+ (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL)
+WHERE seq.id IS NULL OR idx.id IS NULL;
+
RESET enable_seqscan;
RESET enable_indexscan;
RESET enable_bitmapscan;
--
2.7.4
--------------B01ADF66983FA504E371CA13--
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-02-24 08:27 Kyotaro Horiguchi <[email protected]>
0 siblings, 1 reply; 118+ messages in thread
From: Kyotaro Horiguchi @ 2022-02-24 08:27 UTC (permalink / raw)
To: [email protected]; +Cc: [email protected]; pgsql-hackers
At Thu, 24 Feb 2022 16:26:42 +0900 (JST), Kyotaro Horiguchi <[email protected]> wrote in
> So, actually WAL did not ended in an incomplete record. I think
> FinishWalRecover is the last place to do that. (But it could be
> earlier.)
After some investigation, I finally concluded that we should reset
abortedRecPtr and missingContrecPtr at processing
XLOG_OVERWRITE_CONTRECORD.
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -1953,6 +1953,11 @@ xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI)
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
timestamptz_to_str(xlrec.overwrite_time))));
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
/* Verifying the record should only happen once */
record->overwrittenRecPtr = InvalidXLogRecPtr;
}
The last check in the test against "resetting aborted record" is no
longer useful since it is already checked by
026_verwrite_contrecord.pl.
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-02-25 21:28 Imseih (AWS), Sami <[email protected]>
parent: Kyotaro Horiguchi <[email protected]>
0 siblings, 1 reply; 118+ messages in thread
From: Imseih (AWS), Sami @ 2022-02-25 21:28 UTC (permalink / raw)
To: Kyotaro Horiguchi <[email protected]>; +Cc: [email protected] <[email protected]>; pgsql-hackers
> After some investigation, I finally concluded that we should reset
> abortedRecPtr and missingContrecPtr at processing
> XLOG_OVERWRITE_CONTRECORD.
> --- a/src/backend/access/transam/xlogrecovery.c
> +++ b/src/backend/access/transam/xlogrecovery.c
> @@ -1953,6 +1953,11 @@ xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI)
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
timestamptz_to_str(xlrec.overwrite_time))));
> + /* We have safely skipped the aborted record */
> + abortedRecPtr = InvalidXLogRecPtr;
> + missingContrecPtr = InvalidXLogRecPtr;
> +
> /* Verifying the record should only happen once */
> record->overwrittenRecPtr = InvalidXLogRecPtr;
> }
> The last check in the test against "resetting aborted record" is no
> longer useful since it is already checked by
> 026_verwrite_contrecord.pl.
> regards.
+1 for this. Resetting abortedRecPtr and missingContrecPtr after the broken record is skipped in is cleaner. I also think it would make sense to move the " successfully skipped missing contrecord" to after we invalidate the aborted and missing record pointers, like below.
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -1948,15 +1948,15 @@ xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI)
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
LSN_FORMAT_ARGS(record->overwrittenRecPtr));
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
timestamptz_to_str(xlrec.overwrite_time))));
Also, instead of a new test, the current 026_overwrite_contrecord.pl test can include a promotion test at the end.
Attaching a new patch for review.
--
Sami Imseih
Amazon Web Services
Attachments:
[application/octet-stream] v4-0001-Fix-missing-continuation-record-after-standby-promot.patch (2.4K, ../../[email protected]/2-v4-0001-Fix-missing-continuation-record-after-standby-promot.patch)
download | inline diff:
From a43c4dc01c27a07798c935cbc15260d1a668d3b9 Mon Sep 17 00:00:00 2001
From: "Sami Imseih (AWS)" <[email protected]>
Date: Fri, 25 Feb 2022 21:23:34 +0000
Subject: [PATCH 1/1] Fix "missing continuation record" after standby promotion
Invalidate abortedRecPtr and missingContrecPtr after a missing
continuation record is skipped on a standby. This fixes a PANIC
caused when a recently promoted standby attempts to write an
OVERWRITE_RECORD with an LSN of the previously read aborted record.
Author: Sami Imseih
Reviewed-by: Kyotaro Horiguchi <[email protected]>, Alvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
src/backend/access/transam/xlogrecovery.c | 4 ++++
src/test/recovery/t/026_overwrite_contrecord.pl | 5 ++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index f9f212680b..bbb2d7fef5 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -1948,6 +1948,10 @@ xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI)
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
LSN_FORMAT_ARGS(record->overwrittenRecPtr));
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index 0fd907f152..fe175f5e90 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -13,7 +13,7 @@ use Test::More;
# Test: Create a physical replica that's missing the last WAL file,
# then restart the primary to create a divergent WAL file and observe
# that the replica replays the "overwrite contrecord" from that new
-# file.
+# file and the standby promotes successfully.
my $node = PostgreSQL::Test::Cluster->new('primary');
$node->init(allows_streaming => 1);
@@ -100,6 +100,9 @@ like(
qr[successfully skipped missing contrecord at],
"found log line in standby");
+# Verify promotion is successful
+$node_standby->safe_psql('postgres', "select pg_promote()");
+
$node->stop;
$node_standby->stop;
--
2.32.0
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-03-07 20:34 Imseih (AWS), Sami <[email protected]>
parent: Imseih (AWS), Sami <[email protected]>
0 siblings, 2 replies; 118+ messages in thread
From: Imseih (AWS), Sami @ 2022-03-07 20:34 UTC (permalink / raw)
To: Kyotaro Horiguchi <[email protected]>; [email protected] <[email protected]>; +Cc: pgsql-hackers
I have gone ahead and backpatched this all the way to 10 as well.
--
Sami Imseih
Amazon Web Services
Attachments:
[application/octet-stream] v4-0001-Fix-missing-continuation-record-after-standby-promot-v10.patch (2.5K, ../../[email protected]/2-v4-0001-Fix-missing-continuation-record-after-standby-promot-v10.patch)
download | inline diff:
From ae10aaed56ba309bcb8a32d74a7f5fc9ea466c5c Mon Sep 17 00:00:00 2001
From: "Sami Imseih (AWS)" <[email protected]>
Date: Mon, 7 Mar 2022 19:43:50 +0000
Subject: [PATCH 1/1] Fix "missing continuation record" after standby promotion
Invalidate abortedRecPtr and missingContrecPtr after a missing
continuation record is skipped on a standby. This fixes a PANIC
caused when a recently promoted standby attempts to write an
OVERWRITE_RECORD with an LSN of the previously read aborted record.
Author: Sami Imseih
Reviewed-by: Kyotaro Horiguchi <[email protected]>, Alvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch to 10
---
src/backend/access/transam/xlog.c | 4 ++++
src/test/recovery/t/026_overwrite_contrecord.pl | 8 +++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index c64febdb53..76fe62af33 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -10260,6 +10260,10 @@ VerifyOverwriteContrecord(xl_overwrite_contrecord *xlrec, XLogReaderState *state
(uint32) (state->overwrittenRecPtr >> 32),
(uint32) state->overwrittenRecPtr);
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
(uint32) (xlrec->overwritten_lsn >> 32),
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index 57b2a6b7fb..ef962b1271 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -15,7 +15,7 @@ plan tests => 3;
# Test: Create a physical replica that's missing the last WAL file,
# then restart the primary to create a divergent WAL file and observe
# that the replica replays the "overwrite contrecord" from that new
-# file.
+# file and the standby promotes successfully.
my $node = PostgresNode->get_new_node('primary');
$node->init(allows_streaming => 1);
@@ -105,5 +105,11 @@ like(
qr[successfully skipped missing contrecord at],
"found log line in standby");
+# Verify promotion is successful
+$ENV{PGDATA} = $node_standby->data_dir;
+$ENV{PGPORT} = $node_standby->port;
+$ENV{PGGHOST} = $node_standby->host;
+system "pg_ctl promote";
+
$node->stop;
$node_standby->stop;
--
2.32.0
[application/octet-stream] v4-0001-Fix-missing-continuation-record-after-standby-promot-v11.patch (2.5K, ../../[email protected]/3-v4-0001-Fix-missing-continuation-record-after-standby-promot-v11.patch)
download | inline diff:
From 6fab9a83c7a6fce4f2fdd748697f23921a5df2ed Mon Sep 17 00:00:00 2001
From: "Sami Imseih (AWS)" <[email protected]>
Date: Mon, 7 Mar 2022 19:49:32 +0000
Subject: [PATCH 1/1] Fix "missing continuation record" after standby promotion
Invalidate abortedRecPtr and missingContrecPtr after a missing
continuation record is skipped on a standby. This fixes a PANIC
caused when a recently promoted standby attempts to write an
OVERWRITE_RECORD with an LSN of the previously read aborted record.
Author: Sami Imseih
Reviewed-by: Kyotaro Horiguchi <[email protected]>, Alvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch to 10
---
src/backend/access/transam/xlog.c | 4 ++++
src/test/recovery/t/026_overwrite_contrecord.pl | 8 +++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 12992f5f3d..5afb3a5f1d 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -10296,6 +10296,10 @@ VerifyOverwriteContrecord(xl_overwrite_contrecord *xlrec, XLogReaderState *state
(uint32) (state->overwrittenRecPtr >> 32),
(uint32) state->overwrittenRecPtr);
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
(uint32) (xlrec->overwritten_lsn >> 32),
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index 867b75937e..f51547e149 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -15,7 +15,7 @@ plan tests => 3;
# Test: Create a physical replica that's missing the last WAL file,
# then restart the primary to create a divergent WAL file and observe
# that the replica replays the "overwrite contrecord" from that new
-# file.
+# file and the standby promotes successfully.
my $node = PostgresNode->get_new_node('primary');
$node->init(allows_streaming => 1);
@@ -102,5 +102,11 @@ like(
qr[successfully skipped missing contrecord at],
"found log line in standby");
+# Verify promotion is successful
+$ENV{PGDATA} = $node_standby->data_dir;
+$ENV{PGPORT} = $node_standby->port;
+$ENV{PGGHOST} = $node_standby->host;
+system "pg_ctl promote";
+
$node->stop;
$node_standby->stop;
--
2.32.0
[application/octet-stream] v4-0001-Fix-missing-continuation-record-after-standby-promot-v12.patch (2.4K, ../../[email protected]/4-v4-0001-Fix-missing-continuation-record-after-standby-promot-v12.patch)
download | inline diff:
From 4daed94b2c32c1eb11cf37e87d11ea2c5ae803cd Mon Sep 17 00:00:00 2001
From: "Sami Imseih (AWS)" <[email protected]>
Date: Fri, 4 Mar 2022 19:51:15 +0000
Subject: [PATCH 1/1] Fix "missing continuation record" after standby promotion
Invalidate abortedRecPtr and missingContrecPtr after a missing
continuation record is skipped on a standby. This fixes a PANIC
caused when a recently promoted standby attempts to write an
OVERWRITE_RECORD with an LSN of the previously read aborted record.
Author: Sami Imseih
Reviewed-by: Kyotaro Horiguchi <[email protected]>, Alvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch to 10
---
src/backend/access/transam/xlog.c | 4 ++++
src/test/recovery/t/026_overwrite_contrecord.pl | 5 ++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 885558f291..8c7bb1dc6f 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -10148,6 +10148,10 @@ VerifyOverwriteContrecord(xl_overwrite_contrecord *xlrec, XLogReaderState *state
(uint32) (state->overwrittenRecPtr >> 32),
(uint32) state->overwrittenRecPtr);
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
(uint32) (xlrec->overwritten_lsn >> 32),
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index 867b75937e..9115b5ffc9 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -15,7 +15,7 @@ plan tests => 3;
# Test: Create a physical replica that's missing the last WAL file,
# then restart the primary to create a divergent WAL file and observe
# that the replica replays the "overwrite contrecord" from that new
-# file.
+# file and the standby promotes successfully.
my $node = PostgresNode->get_new_node('primary');
$node->init(allows_streaming => 1);
@@ -102,5 +102,8 @@ like(
qr[successfully skipped missing contrecord at],
"found log line in standby");
+# Verify promotion is successful
+$node_standby->safe_psql('postgres', "select pg_promote()");
+
$node->stop;
$node_standby->stop;
--
2.32.0
[application/octet-stream] v4-0001-Fix-missing-continuation-record-after-standby-promot-v13.patch (2.4K, ../../[email protected]/5-v4-0001-Fix-missing-continuation-record-after-standby-promot-v13.patch)
download | inline diff:
From 79fb2465daf73bf9f710e55860f68df755d614b8 Mon Sep 17 00:00:00 2001
From: "Sami Imseih (AWS)" <[email protected]>
Date: Fri, 4 Mar 2022 23:57:02 +0000
Subject: [PATCH 1/1] Fix "missing continuation record" after standby promotion
Invalidate abortedRecPtr and missingContrecPtr after a missing
continuation record is skipped on a standby. This fixes a PANIC
caused when a recently promoted standby attempts to write an
OVERWRITE_RECORD with an LSN of the previously read aborted record.
Author: Sami Imseih
Reviewed-by: Kyotaro Horiguchi <[email protected]>, Alvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch to 10
---
src/backend/access/transam/xlog.c | 4 ++++
src/test/recovery/t/026_overwrite_contrecord.pl | 5 ++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 3d76fad128..a472e26328 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -10382,6 +10382,10 @@ VerifyOverwriteContrecord(xl_overwrite_contrecord *xlrec, XLogReaderState *state
(uint32) (state->overwrittenRecPtr >> 32),
(uint32) state->overwrittenRecPtr);
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
(uint32) (xlrec->overwritten_lsn >> 32),
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index cb7f5b68c6..2577afc98b 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -15,7 +15,7 @@ plan tests => 3;
# Test: Create a physical replica that's missing the last WAL file,
# then restart the primary to create a divergent WAL file and observe
# that the replica replays the "overwrite contrecord" from that new
-# file.
+# file and the standby promotes successfully.
my $node = PostgresNode->get_new_node('primary');
$node->init(allows_streaming => 1);
@@ -102,5 +102,8 @@ like(
qr[successfully skipped missing contrecord at],
"found log line in standby");
+# Verify promotion is successful
+$node_standby->safe_psql('postgres', "select pg_promote()");
+
$node->stop;
$node_standby->stop;
--
2.32.0
[application/octet-stream] v4-0001-Fix-missing-continuation-record-after-standby-promot-v14.patch (2.4K, ../../[email protected]/6-v4-0001-Fix-missing-continuation-record-after-standby-promot-v14.patch)
download | inline diff:
From 8332d475825f05f5c9f7f48537d4c5cbbc6f29c4 Mon Sep 17 00:00:00 2001
From: "Sami Imseih (AWS)" <[email protected]>
Date: Fri, 4 Mar 2022 19:10:18 +0000
Subject: [PATCH 1/1] Fix "missing continuation record" after standby promotion
Invalidate abortedRecPtr and missingContrecPtr after a missing
continuation record is skipped on a standby. This fixes a PANIC
caused when a recently promoted standby attempts to write an
OVERWRITE_RECORD with an LSN of the previously read aborted record.
Author: Sami Imseih
Reviewed-by: Kyotaro Horiguchi <[email protected]>, Alvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch to 10
---
src/backend/access/transam/xlog.c | 4 ++++
src/test/recovery/t/026_overwrite_contrecord.pl | 5 ++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 6208e123e5..b241f33f7e 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -10591,6 +10591,10 @@ VerifyOverwriteContrecord(xl_overwrite_contrecord *xlrec, XLogReaderState *state
LSN_FORMAT_ARGS(xlrec->overwritten_lsn),
LSN_FORMAT_ARGS(state->overwrittenRecPtr));
+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
LSN_FORMAT_ARGS(xlrec->overwritten_lsn),
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index cb7f5b68c6..2577afc98b 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -15,7 +15,7 @@ plan tests => 3;
# Test: Create a physical replica that's missing the last WAL file,
# then restart the primary to create a divergent WAL file and observe
# that the replica replays the "overwrite contrecord" from that new
-# file.
+# file and the standby promotes successfully.
my $node = PostgresNode->get_new_node('primary');
$node->init(allows_streaming => 1);
@@ -102,5 +102,8 @@ like(
qr[successfully skipped missing contrecord at],
"found log line in standby");
+# Verify promotion is successful
+$node_standby->safe_psql('postgres', "select pg_promote()");
+
$node->stop;
$node_standby->stop;
--
2.32.0
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-03-23 17:24 [email protected] <[email protected]>
parent: Imseih (AWS), Sami <[email protected]>
1 sibling, 0 replies; 118+ messages in thread
From: [email protected] @ 2022-03-23 17:24 UTC (permalink / raw)
To: Imseih (AWS), Sami <[email protected]>; +Cc: Kyotaro Horiguchi <[email protected]>; pgsql-hackers
On 2022-Mar-07, Imseih (AWS), Sami wrote:
> I have gone ahead and backpatched this all the way to 10 as well.
Thanks! I pushed this now. I edited the test though: I don't
understand why you went to the trouble of setting stuff in order to call
'pg_ctl promote' (in different ways for older branches), when
$node_standby->promote does the same and is simpler to call. So I
changed the tests to do that. (I did verify that without the code fix,
the PANIC indeed is thrown.)
Thank again,
--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-05-26 19:57 Imseih (AWS), Sami <[email protected]>
parent: Imseih (AWS), Sami <[email protected]>
1 sibling, 2 replies; 118+ messages in thread
From: Imseih (AWS), Sami @ 2022-05-26 19:57 UTC (permalink / raw)
To: Kyotaro Horiguchi <[email protected]>; [email protected] <[email protected]>; +Cc: pgsql-hackers
We see another occurrence of this bug with the last patch applied in 13.7.
After a promotion we observe the following in the logs:
2022-05-25 00:35:38 UTC::@:[371]:PANIC: xlog flush request 10/B1FA3D88 is not satisfied --- flushed only to 7/A8000060
2022-05-25 00:35:38 UTC:172.31.26.238(38610):administrator@postgres:[23433]:ERROR: current transaction is aborted, commands ignored until end of transaction block
However, The logs do not show "LOG: successfully skipped missing contrecord",
therefore we know that VerifyOverwriteContrecord
is not being called to invalidate the missingContrecPtr.
VerifyOverwriteContrecord(xl_overwrite_contrecord *xlrec, XLogReaderState *state)
{
if (xlrec->overwritten_lsn != state->overwrittenRecPtr)
elog(FATAL, "mismatching overwritten LSN %X/%X -> %X/%X",
(uint32) (xlrec->overwritten_lsn >> 32),
(uint32) xlrec->overwritten_lsn,
(uint32) (state->overwrittenRecPtr >> 32),
(uint32) state->overwrittenRecPtr);
/* We have safely skipped the aborted record */
abortedRecPtr = InvalidXLogRecPtr;
missingContrecPtr = InvalidXLogRecPtr;
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
(uint32) (xlrec->overwritten_lsn >> 32),
(uint32) xlrec->overwritten_lsn,
timestamptz_to_str(xlrec->overwrite_time))));
We think it's because VerifyOverwriteContrecord was not
called which is why we see this behavior.
Are there are other places where missingContrecPtr
should be invalidated, such as after a successful promotion?
--
Sami Imseih
Amazon Web Services
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-05-27 01:59 Kyotaro Horiguchi <[email protected]>
parent: Imseih (AWS), Sami <[email protected]>
1 sibling, 0 replies; 118+ messages in thread
From: Kyotaro Horiguchi @ 2022-05-27 01:59 UTC (permalink / raw)
To: [email protected]; +Cc: [email protected]; pgsql-hackers
At Thu, 26 May 2022 19:57:41 +0000, "Imseih (AWS), Sami" <[email protected]> wrote in
> We see another occurrence of this bug with the last patch applied in 13.7.
>
> After a promotion we observe the following in the logs:
...
> We think it's because VerifyOverwriteContrecord was not
> called which is why we see this behavior.
>
> Are there are other places where missingContrecPtr
> should be invalidated, such as after a successful promotion?
The only cause known to me for EndOfLog being moved to such location
is missingContrecPtr. But if the next record is not
XLOG_OVERWRITE_CONTRECORD recovery should have stopped there. And if
XLOG_OVERWRITE_CONTRECORD is there, VerifyOverwriteContrecord should
have been called..
Could you inspect WAL files of the environment and see if the first
record of the '7/A8'th segment OVERWRITE_CONTRECORD? I don't say that
makes some progress on this, but could be the first step.
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-05-27 02:01 Imseih (AWS), Sami <[email protected]>
parent: Imseih (AWS), Sami <[email protected]>
1 sibling, 1 reply; 118+ messages in thread
From: Imseih (AWS), Sami @ 2022-05-27 02:01 UTC (permalink / raw)
To: Kyotaro Horiguchi <[email protected]>; [email protected] <[email protected]>; +Cc: pgsql-hackers
After further research, we found the following.
Testing on 13.6 with the attached patch we see
that the missingContrecPtr is being incorrectly
set on the standby and the promote in the tap
test fails.
Per the comments in xlog.c, the
missingContrecPtr should not be set when
in standby mode.
/*
* When not in standby mode we find that WAL ends in an incomplete
* record, keep track of that record. After recovery is done,
* we'll write a record to indicate downstream WAL readers that
* that portion is to be ignored.
*/
if (!StandbyMode &&
!XLogRecPtrIsInvalid(xlogreader->abortedRecPtr))
{
abortedRecPtr = xlogreader->abortedRecPtr;
missingContrecPtr = xlogreader->missingContrecPtr;
elog(LOG, "missingContrecPtr == %ld", missingContrecPtr);
}
If StandbyModeRequested is checked instead, which
checks for the presence of a standby signal file,
The missingContrecPtr is not set on the
standby and the test succeeds.
if (!StandbyModeRequested &&
!XLogRecPtrIsInvalid(xlogreader->abortedRecPtr))
{
abortedRecPtr = xlogreader->abortedRecPtr;
missingContrecPtr = xlogreader->missingContrecPtr;
elog(LOG, "missingContrecPtr == %ld", missingContrecPtr);
}
If this is a bug as it appears, it appears the original patch
to resolve this issue is not needed and the ideal fix
Is to ensure that a standby does not set
missingContrecPtr.
Would like to see what others think.
Thanks
--
Sami Imseih
Amazon Web Services
Attachments:
[application/octet-stream] 0001-Testing_patch[2][2].patch (1.5K, ../../[email protected]/2-0001-Testing_patch%5B2%5D%5B2%5D.patch)
download | inline diff:
From 736308047747c7b1e5b78dacf95a0b8459d2b7a1 Mon Sep 17 00:00:00 2001
From: "Imseih (AWS)" <[email protected]>
Date: Thu, 26 May 2022 19:41:22 -0500
Subject: [PATCH 1/1] Testing_patch
---
src/backend/access/transam/xlog.c | 2 ++
src/test/recovery/t/026_overwrite_contrecord.pl | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 3d76fad..a1b78f3 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4381,6 +4381,7 @@ ReadRecord(XLogReaderState *xlogreader, int emode,
{
abortedRecPtr = xlogreader->abortedRecPtr;
missingContrecPtr = xlogreader->missingContrecPtr;
+ elog(LOG, "missingContrecPtr == %ld", missingContrecPtr);
}
if (readFile >= 0)
@@ -4398,6 +4399,7 @@ ReadRecord(XLogReaderState *xlogreader, int emode,
if (errormsg)
ereport(emode_for_corrupt_record(emode, EndRecPtr),
(errmsg_internal("%s", errormsg) /* already translated */ ));
+
}
/*
diff --git a/src/test/recovery/t/026_overwrite_contrecord.pl b/src/test/recovery/t/026_overwrite_contrecord.pl
index cb7f5b6..a3000f1 100644
--- a/src/test/recovery/t/026_overwrite_contrecord.pl
+++ b/src/test/recovery/t/026_overwrite_contrecord.pl
@@ -101,6 +101,6 @@ like(
$log,
qr[successfully skipped missing contrecord at],
"found log line in standby");
-
+$node_standby->promote;
$node->stop;
$node_standby->stop;
--
2.32.1 (Apple Git-133)
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-05-27 06:37 Kyotaro Horiguchi <[email protected]>
parent: Imseih (AWS), Sami <[email protected]>
0 siblings, 1 reply; 118+ messages in thread
From: Kyotaro Horiguchi @ 2022-05-27 06:37 UTC (permalink / raw)
To: [email protected]; +Cc: [email protected]; pgsql-hackers
At Fri, 27 May 2022 02:01:27 +0000, "Imseih (AWS), Sami" <[email protected]> wrote in
> After further research, we found the following.
>
> Testing on 13.6 with the attached patch we see
> that the missingContrecPtr is being incorrectly
> set on the standby and the promote in the tap
> test fails.
>
> Per the comments in xlog.c, the
> missingContrecPtr should not be set when
> in standby mode.
>
> /*
> * When not in standby mode we find that WAL ends in an incomplete
> * record, keep track of that record. After recovery is done,
> * we'll write a record to indicate downstream WAL readers that
> * that portion is to be ignored.
> */
> if (!StandbyMode &&
> !XLogRecPtrIsInvalid(xlogreader->abortedRecPtr))
> {
> abortedRecPtr = xlogreader->abortedRecPtr;
> missingContrecPtr = xlogreader->missingContrecPtr;
> elog(LOG, "missingContrecPtr == %ld", missingContrecPtr);
> }
>
> If StandbyModeRequested is checked instead, which
> checks for the presence of a standby signal file,
> The missingContrecPtr is not set on the
> standby and the test succeeds.
>
> if (!StandbyModeRequested &&
> !XLogRecPtrIsInvalid(xlogreader->abortedRecPtr))
> {
> abortedRecPtr = xlogreader->abortedRecPtr;
> missingContrecPtr = xlogreader->missingContrecPtr;
> elog(LOG, "missingContrecPtr == %ld", missingContrecPtr);
> }
>
> If this is a bug as it appears, it appears the original patch
> to resolve this issue is not needed and the ideal fix
> Is to ensure that a standby does not set
> missingContrecPtr.
>
> Would like to see what others think.
Due to lack of information, I don't have a clear idea of what is
happening here. If that change "fixed" the "issue", that seems to mean
that crash recovery passed an immature contrecord (@6/A8000060) but
recovery did not stop at the time then continues until 10/B1FA3D88. A
possibility is, crash recovery ended at the immature contrecord then
the server moved to archive recovery mode and was able to continue
from the same (aborted) LSN on the archived WAL. This means 6/A8 in
pg_wal had been somehow removed after archived, or the segment 6/A7
(not A8) in both pg_xlog and archive are in different histories, which
seems to me what we wanted to prevent by the
XLOG_OVERWRITE_CONTRECORD. Didn't you use the same archive content
for repeated recovery testing?
And from the fact that entering crash recovery means the cluster
didn't have an idea of how far it should recover until consistency,
that is contained in backup label control file. That could happen
when a crashed primary is as-is reused as the new standby of the new
primary.
So.. I'd like to hear exactly what you did as the testing.
When standby mode is requested, if crash recovery fails with immature
contrecord, I think we shouldn't continue recovery. But I'm not sure
we need to explictly reject that case. Further study is needed..
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
^ permalink raw reply [nested|flat] 118+ messages in thread
* Re: [BUG] Panic due to incorrect missingContrecPtr after promotion
@ 2022-05-27 19:01 Imseih (AWS), Sami <[email protected]>
parent: Kyotaro Horiguchi <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Imseih (AWS), Sami @ 2022-05-27 19:01 UTC (permalink / raw)
To: Kyotaro Horiguchi <[email protected]>; +Cc: [email protected] <[email protected]>; pgsql-hackers
> So.. I'd like to hear exactly what you did as the testing.
> When standby mode is requested, if crash recovery fails with immature
> contrecord, I think we shouldn't continue recovery. But I'm not sure
> we need to explictly reject that case. Further study is needed..
Here is more details about my findings and testing.
Even with commit 9d92582abf918215d27659d45a4c9e78bda50aff
we still see the issue with post promotion checkpoint
resulting in "request to flush past end of generated WAL;"
i.e.
2022-05-25 00:35:38 UTC::@:[371]:LOG: checkpoint starting: immediate force wait wal time
2022-05-25 00:35:38 UTC::@:[371]:LOG: request to flush past end of generated WAL; request 10/B1FA3D88, currpos 7/A8000060
2022-05-25 00:35:38 UTC::@:[371]:PANIC: xlog flush request 10/B1FA3D88 is not satisfied --- flushed only to 7/A8000060
2022-05-25 00:35:38 UTC:172.31.26.238(38610):administrator@postgres:[23433]:ERROR: current transaction is aborted, commands ignored until end of transaction block
The intent of commit 9d92582abf918215d27659d45a4c9e78bda50aff
was to make sure the standby skips the overwrite contrecord.
However, we still see "missingContrecPtr" is being set
on the standby before promotion and after the instance is
promoted, the missingContrecPtr is written to WAL
and the subsequent flush throws a "PANIC: xlog flush request"
To Reproduce using TAP tests;
1) apply the attached patch 0001-Patch_to_repro.patch to the head branch.
This patch adds logging when an OverWriteContRecord
is created and comments out the invalidation code
added in commit 9d92582abf918215d27659d45a4c9e78bda50aff
2) Run a tap test under "test/recovery"
make check PROVE_TESTS='t/026_overwrite_contrecord.pl'
3) What is observed in the logfiles for both the standby
and primary instance in the tap test is
that an overwrite contrecord is created on the primary,
which is correct, but also on the standby after promotion,
which is incorrect. This is incorrect as the contrecord
simseih@88665a22795f recovery % cat tmp_check/log/*prim* | grep 'creating\|promo'
2022-05-27 13:17:50.843 CDT [98429] LOG: creating overwrite contrecord at 0/2000058 for aborted_lsn 0/1FFD000
simseih@88665a22795f recovery % cat tmp_check/log/*stan* | grep 'creating\|promo'
2022-05-27 13:17:51.361 CDT [98421] LOG: received promote request
2022-05-27 13:17:51.394 CDT [98421] LOG: creating overwrite contrecord at 0/2000058 for aborted_lsn 0/1FFD000
simseih@88665a22795f recovery %
What we found:
1. missingContrecPtr is set when
StandbyMode is false, therefore
only a writer should set this value
and a record is then sent downstream.
But a standby going through crash
recovery will always have StandbyMode = false,
causing the missingContrecPtr to be incorrectly
set.
2. If StandbyModeRequested is checked instead,
we ensure that a standby will not set a
missingContrecPtr.
3. After applying the patch below, the tap test succeeded
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 5ee90b6..a727aaf 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -2977,7 +2977,7 @@ ReadRecord(XLogPrefetcher *xlogprefetcher, int emode,
* we'll write a record to indicate to downstream WAL readers that
* that portion is to be ignored.
*/
- if (!StandbyMode &&
+ if (!StandbyModeRequested &&
!XLogRecPtrIsInvalid(xlogreader->abortedRecPtr))
{
abortedRecPtr = xlogreader->abortedRecPtr;
So, it might be that the best fix is not the commit in 9d92582abf918215d27659d45a4c9e78bda50aff
but to check StandbyModeRequested = false before setting
missingContrecPtr.
Thank you
---
Sami Imseih
Amazon Web Services
Attachments:
[application/octet-stream] 0001-Patch_to_repro.patch (1.6K, ../../[email protected]/2-0001-Patch_to_repro.patch)
download | inline diff:
From 657570f32c8151dcd74eeb4810d97b090c3ac889 Mon Sep 17 00:00:00 2001
From: "Imseih (AWS)" <[email protected]>
Date: Fri, 27 May 2022 13:28:50 -0500
Subject: [PATCH 1/1] Patch_to_repro
---
src/backend/access/transam/xlog.c | 2 ++
src/backend/access/transam/xlogrecovery.c | 4 ++--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 71136b1..dc301ed 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -6813,6 +6813,8 @@ CreateOverwriteContrecordRecord(XLogRecPtr aborted_lsn, XLogRecPtr pagePtr,
elog(ERROR, "OVERWRITE_CONTRECORD was inserted to unexpected position %X/%X",
LSN_FORMAT_ARGS(ProcLastRecPtr));
+ elog(LOG, "creating overwrite contrecord at %X/%X for aborted_lsn %X/%X",
+ LSN_FORMAT_ARGS(recptr), LSN_FORMAT_ARGS(aborted_lsn));
XLogFlush(recptr);
END_CRIT_SECTION();
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 6eba626..5ee90b6 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -1971,8 +1971,8 @@ xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI)
LSN_FORMAT_ARGS(record->overwrittenRecPtr));
/* We have safely skipped the aborted record */
- abortedRecPtr = InvalidXLogRecPtr;
- missingContrecPtr = InvalidXLogRecPtr;
+ //abortedRecPtr = InvalidXLogRecPtr;
+ //missingContrecPtr = InvalidXLogRecPtr;
ereport(LOG,
(errmsg("successfully skipped missing contrecord at %X/%X, overwritten at %s",
--
2.32.1 (Apple Git-133)
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs).
@ 2023-06-25 11:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 18 ++++++++--
3 files changed, 136 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..23ee285b40 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,57 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..c0fc16d773 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses.
+
+<synopsis>
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Jun_25_21_05_09_2023_126)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v1-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs).
@ 2023-06-25 11:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 18 ++++++++--
3 files changed, 136 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..23ee285b40 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,57 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..c0fc16d773 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses.
+
+<synopsis>
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Jun_25_21_05_09_2023_126)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v1-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs).
@ 2023-06-25 11:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 18 ++++++++--
3 files changed, 136 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..23ee285b40 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,57 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..c0fc16d773 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses.
+
+<synopsis>
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Jun_25_21_05_09_2023_126)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v1-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs).
@ 2023-06-25 11:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 18 ++++++++--
3 files changed, 136 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..23ee285b40 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,57 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..c0fc16d773 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses.
+
+<synopsis>
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Jun_25_21_05_09_2023_126)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v1-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs).
@ 2023-06-26 08:05 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++--
3 files changed, 148 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..e9bbd5bc7c 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jun_26_17_45_07_2023_724)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v2-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs).
@ 2023-06-26 08:05 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++--
3 files changed, 148 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..e9bbd5bc7c 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jun_26_17_45_07_2023_724)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v2-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs).
@ 2023-06-26 08:05 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++--
3 files changed, 148 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..e9bbd5bc7c 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jun_26_17_45_07_2023_724)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v2-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs).
@ 2023-06-26 08:05 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++--
3 files changed, 148 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..e9bbd5bc7c 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jun_26_17_45_07_2023_724)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v2-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs).
@ 2023-06-26 08:05 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++--
3 files changed, 148 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..e9bbd5bc7c 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Window function <function>rpr</function> can be used with row pattern
+ common syntax to perform row pattern recognition in a query. Row pattern
+ common syntax includes two sub clauses. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An
+ example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, rpr(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8069c58ca5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>rpr</primary>
+ </indexterm>
+ <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Perform row pattern recognition using column specified
+ by <parameter>value</parameter> and returns the value of the column if
+ current row is the first matching row;
+ returns <literal>NULL</literal> otherwise.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jun_26_17_45_07_2023_724)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v2-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs).
@ 2023-07-26 10:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++--
3 files changed, 133 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dcc9d6f59d..b333d62410 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v3-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs).
@ 2023-07-26 10:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++--
3 files changed, 133 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dcc9d6f59d..b333d62410 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v3-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs).
@ 2023-07-26 10:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++--
3 files changed, 133 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dcc9d6f59d..b333d62410 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v3-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs).
@ 2023-07-26 10:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++--
3 files changed, 133 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dcc9d6f59d..b333d62410 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v3-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs).
@ 2023-07-26 10:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++--
3 files changed, 133 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dcc9d6f59d..b333d62410 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v3-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs).
@ 2023-08-09 07:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be2f54c914..6cda164522 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Aug__9_17_41_12_2023_134)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v4-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs).
@ 2023-08-09 07:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be2f54c914..6cda164522 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Aug__9_17_41_12_2023_134)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v4-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs).
@ 2023-08-09 07:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be2f54c914..6cda164522 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Aug__9_17_41_12_2023_134)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v4-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs).
@ 2023-08-09 07:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be2f54c914..6cda164522 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Aug__9_17_41_12_2023_134)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v4-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs).
@ 2023-08-09 07:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be2f54c914..6cda164522 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Aug__9_17_41_12_2023_134)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v4-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs).
@ 2023-08-09 07:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be2f54c914..6cda164522 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Aug__9_17_41_12_2023_134)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v4-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7a0d4b9134..b7bfc9271e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Sep__2_15_52_35_2023_273)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v5-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7a0d4b9134..b7bfc9271e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Sep__2_15_52_35_2023_273)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v5-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7a0d4b9134..b7bfc9271e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Sep__2_15_52_35_2023_273)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v5-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7a0d4b9134..b7bfc9271e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Sep__2_15_52_35_2023_273)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v5-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7a0d4b9134..b7bfc9271e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Sep__2_15_52_35_2023_273)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v5-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7a0d4b9134..b7bfc9271e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Sep__2_15_52_35_2023_273)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v5-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs).
@ 2023-09-12 05:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Sep_12_15_18_43_2023_359)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v6-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs).
@ 2023-09-12 05:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Sep_12_15_18_43_2023_359)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v6-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs).
@ 2023-09-12 05:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Sep_12_15_18_43_2023_359)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v6-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs).
@ 2023-09-12 05:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Sep_12_15_18_43_2023_359)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v6-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs).
@ 2023-09-12 05:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Sep_12_15_18_43_2023_359)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v6-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs).
@ 2023-09-12 05:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..8d3becd57a 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Sep_12_15_18_43_2023_359)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v6-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs).
@ 2023-09-22 04:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Sep_22_14_16_40_2023_530)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v7-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs).
@ 2023-09-22 04:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Sep_22_14_16_40_2023_530)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v7-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs).
@ 2023-09-22 04:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Sep_22_14_16_40_2023_530)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v7-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs).
@ 2023-09-22 04:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Sep_22_14_16_40_2023_530)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v7-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs).
@ 2023-09-22 04:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Sep_22_14_16_40_2023_530)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v7-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs).
@ 2023-09-25 05:01 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Sep_25_14_26_30_2023_752)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v8-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs).
@ 2023-09-25 05:01 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Sep_25_14_26_30_2023_752)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v8-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs).
@ 2023-09-25 05:01 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Sep_25_14_26_30_2023_752)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v8-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs).
@ 2023-09-25 05:01 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Sep_25_14_26_30_2023_752)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v8-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs).
@ 2023-09-25 05:01 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..9c99dda4ae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..056768b330 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Sep_25_14_26_30_2023_752)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v8-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs).
@ 2023-10-04 05:51 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index f1ad64c3d6..6c46ea4355 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Oct__4_15_03_28_2023_821)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v9-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs).
@ 2023-10-04 05:51 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index f1ad64c3d6..6c46ea4355 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Oct__4_15_03_28_2023_821)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v9-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs).
@ 2023-10-04 05:51 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index f1ad64c3d6..6c46ea4355 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Oct__4_15_03_28_2023_821)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v9-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs).
@ 2023-10-04 05:51 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++--
3 files changed, 142 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..f39ec8f2d5 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used with row pattern common syntax to
+ perform row pattern recognition in a query. Row pattern common syntax
+ includes two sub clauses. <literal>DEFINE</literal> defines definition
+ variables along with an expression. The expression must be a logical
+ expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. Moreover if the expression comprises a column
+ reference, it must be the argument of <function>rpr</function>. An example
+ of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns price column in the previous
+ row if it's called in a context of row pattern recognition. So in the
+ second line means the definition variable "UP" is <literal>TRUE</literal>
+ when price column in the current row is greater than the price column in
+ the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+ sequence of rows found, rpr returns the column at the starting row.
+ Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index f1ad64c3d6..6c46ea4355 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Oct__4_15_03_28_2023_821)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v9-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs).
@ 2023-10-22 02:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7c3e940afe..1d835af15a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Oct_22_11_39_20_2023_140)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v10-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs).
@ 2023-10-22 02:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7c3e940afe..1d835af15a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Oct_22_11_39_20_2023_140)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v10-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs).
@ 2023-10-22 02:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7c3e940afe..1d835af15a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Oct_22_11_39_20_2023_140)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v10-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs).
@ 2023-10-22 02:22 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7c3e940afe..1d835af15a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Oct_22_11_39_20_2023_140)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v10-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v11 5/7] Row pattern recognition patch (docs).
@ 2023-11-08 06:57 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..c3a8167c8e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21933,6 +21933,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21972,6 +21973,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Nov__8_16_37_05_2023_872)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v11-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v11 5/7] Row pattern recognition patch (docs).
@ 2023-11-08 06:57 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..c3a8167c8e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21933,6 +21933,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21972,6 +21973,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Nov__8_16_37_05_2023_872)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v11-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v11 5/7] Row pattern recognition patch (docs).
@ 2023-11-08 06:57 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..c3a8167c8e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21933,6 +21933,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21972,6 +21973,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 42d78913cf..522ad9dd70 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_Nov__8_16_37_05_2023_872)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v11-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v12 5/7] Row pattern recognition patch (docs).
@ 2023-12-04 11:23 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 20da3ed033..8a18e0ee23 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21935,6 +21935,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21974,6 +21975,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 227ba1993b..dabaca9127 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Dec__8_10_16_13_2023_489)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v12-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v12 5/7] Row pattern recognition patch (docs).
@ 2023-12-04 11:23 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 20da3ed033..8a18e0ee23 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21935,6 +21935,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21974,6 +21975,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 227ba1993b..dabaca9127 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Dec__8_10_16_13_2023_489)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v12-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v12 5/7] Row pattern recognition patch (docs).
@ 2023-12-04 11:23 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 20da3ed033..8a18e0ee23 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21935,6 +21935,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21974,6 +21975,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 227ba1993b..dabaca9127 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Dec__8_10_16_13_2023_489)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v12-0006-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v13 6/8] Row pattern recognition patch (docs).
@ 2024-01-22 09:45 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 210c7c0b02..8422aa6b93 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21941,6 +21941,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21980,6 +21981,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 9917df7839..1575fc2167 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jan_22_19_26_18_2024_011)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v13-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v13 6/8] Row pattern recognition patch (docs).
@ 2024-01-22 09:45 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 210c7c0b02..8422aa6b93 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21941,6 +21941,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21980,6 +21981,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 9917df7839..1575fc2167 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jan_22_19_26_18_2024_011)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v13-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v13 6/8] Row pattern recognition patch (docs).
@ 2024-01-22 09:45 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 210c7c0b02..8422aa6b93 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21941,6 +21941,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -21980,6 +21981,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 9917df7839..1575fc2167 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Jan_22_19_26_18_2024_011)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v13-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v14 6/8] Row pattern recognition patch (docs).
@ 2024-02-28 13:59 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-02-28 13:59 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index e5fa82c161..8dd97501a7 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22364,6 +22364,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22403,6 +22404,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 9917df7839..1575fc2167 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Feb_29_09_19_54_2024_640)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v14-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v14 6/8] Row pattern recognition patch (docs).
@ 2024-02-28 13:59 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-02-28 13:59 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index e5fa82c161..8dd97501a7 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22364,6 +22364,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22403,6 +22404,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 9917df7839..1575fc2167 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Feb_29_09_19_54_2024_640)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v14-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v14 6/8] Row pattern recognition patch (docs).
@ 2024-02-28 13:59 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-02-28 13:59 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index e5fa82c161..8dd97501a7 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22364,6 +22364,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22403,6 +22404,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 9917df7839..1575fc2167 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Feb_29_09_19_54_2024_640)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v14-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs).
@ 2024-03-28 10:30 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 93b0bc2bc6..d25eeb3327 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Mar_28_19_59_25_2024_076)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v15-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs).
@ 2024-03-28 10:30 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 93b0bc2bc6..d25eeb3327 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Mar_28_19_59_25_2024_076)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v15-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs).
@ 2024-03-28 10:30 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 93b0bc2bc6..d25eeb3327 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Mar_28_19_59_25_2024_076)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v15-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs).
@ 2024-03-28 10:30 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 93b0bc2bc6..d25eeb3327 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Mar_28_19_59_25_2024_076)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v15-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs).
@ 2024-03-28 10:30 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 93b0bc2bc6..d25eeb3327 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Mar_28_19_59_25_2024_076)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v15-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v16 6/8] Row pattern recognition patch (docs).
@ 2024-04-12 06:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-04-12 06:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 8dfb42ad4d..f6ee99fe19 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23123,6 +23123,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23162,6 +23163,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Apr_12_16_09_08_2024_262)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v16-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v16 6/8] Row pattern recognition patch (docs).
@ 2024-04-12 06:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-04-12 06:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 8dfb42ad4d..f6ee99fe19 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23123,6 +23123,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23162,6 +23163,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Apr_12_16_09_08_2024_262)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v16-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v16 6/8] Row pattern recognition patch (docs).
@ 2024-04-12 06:49 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-04-12 06:49 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..cf18dd887e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,86 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. Row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. So in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. In the second or
+ subsequent rows all window functions and aggregates are NULL. For rows
+ that do not match the PATTERN, all window functions and aggregates are
+ shown AS NULL too, except count which shows 0. This is because the
+ unmatched rows are in an empty frame. Example of
+ a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+ and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock,
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | |
+ company1 | 2023-07-03 | 150 | | |
+ company1 | 2023-07-04 | 140 | | |
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | |
+ company1 | 2023-07-08 | 130 | | |
+ company1 | 2023-07-09 | 120 | | |
+ company1 | 2023-07-10 | 130 | | | 0
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 8dfb42ad4d..f6ee99fe19 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23123,6 +23123,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23162,6 +23163,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Apr_12_16_09_08_2024_262)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v16-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v17 6/8] Row pattern recognition patch (docs).
@ 2024-04-28 11:00 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-04-28 11:00 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1928de5762..adbcb1f279 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Apr_28_20_28_26_2024_444)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v17-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v17 6/8] Row pattern recognition patch (docs).
@ 2024-04-28 11:00 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-04-28 11:00 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1928de5762..adbcb1f279 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Apr_28_20_28_26_2024_444)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v17-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v17 6/8] Row pattern recognition patch (docs).
@ 2024-04-28 11:00 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-04-28 11:00 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1928de5762..adbcb1f279 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sun_Apr_28_20_28_26_2024_444)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v17-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v18 6/8] Row pattern recognition patch (docs).
@ 2024-05-11 07:11 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_May_11_16_23_07_2024_789)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v18-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v18 6/8] Row pattern recognition patch (docs).
@ 2024-05-11 07:11 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_May_11_16_23_07_2024_789)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v18-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v18 6/8] Row pattern recognition patch (docs).
@ 2024-05-11 07:11 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_May_11_16_23_07_2024_789)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v18-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v19 6/8] Row pattern recognition patch (docs).
@ 2024-05-14 23:26 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-14 23:26 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_May_15_09_02_03_2024_008)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v19-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v19 6/8] Row pattern recognition patch (docs).
@ 2024-05-14 23:26 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-14 23:26 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_May_15_09_02_03_2024_008)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v19-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v19 6/8] Row pattern recognition patch (docs).
@ 2024-05-14 23:26 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-14 23:26 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Wed_May_15_09_02_03_2024_008)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v19-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v20 6/8] Row pattern recognition patch (docs).
@ 2024-05-24 02:26 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-24 02:26 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_May_24_11_39_19_2024_763)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v20-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v20 6/8] Row pattern recognition patch (docs).
@ 2024-05-24 02:26 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-24 02:26 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_May_24_11_39_19_2024_763)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v20-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v20 6/8] Row pattern recognition patch (docs).
@ 2024-05-24 02:26 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-05-24 02:26 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc338..8dbab31300 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 066aed44e6..8f18718d58 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_May_24_11_39_19_2024_763)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v20-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v21 6/8] Row pattern recognition patch (docs).
@ 2024-08-26 04:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-08-26 04:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 461fc3f437..02ad2b0195 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23258,6 +23258,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23297,6 +23298,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Aug_26_13_39_47_2024_878)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v21-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v21 6/8] Row pattern recognition patch (docs).
@ 2024-08-26 04:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-08-26 04:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 461fc3f437..02ad2b0195 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23258,6 +23258,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23297,6 +23298,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Aug_26_13_39_47_2024_878)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v21-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v21 6/8] Row pattern recognition patch (docs).
@ 2024-08-26 04:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-08-26 04:32 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 461fc3f437..02ad2b0195 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23258,6 +23258,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23297,6 +23298,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Aug_26_13_39_47_2024_878)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v21-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v22 6/8] Row pattern recognition patch (docs).
@ 2024-09-19 04:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-09-19 04:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 6f75bd0c7d..4482c80a70 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23261,6 +23261,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23300,6 +23301,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Sep_19_13_59_47_2024_608)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v22-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v22 6/8] Row pattern recognition patch (docs).
@ 2024-09-19 04:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-09-19 04:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 6f75bd0c7d..4482c80a70 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23261,6 +23261,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23300,6 +23301,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Sep_19_13_59_47_2024_608)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v22-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v22 6/8] Row pattern recognition patch (docs).
@ 2024-09-19 04:48 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-09-19 04:48 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 6f75bd0c7d..4482c80a70 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23261,6 +23261,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23300,6 +23301,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Sep_19_13_59_47_2024_608)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v22-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v23 6/8] Row pattern recognition patch (docs).
@ 2024-10-25 03:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-10-25 03:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 58dc06b68b..ef4fa7144f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23263,6 +23263,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23302,6 +23303,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Oct_25_13_04_53_2024_648)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v23-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v23 6/8] Row pattern recognition patch (docs).
@ 2024-10-25 03:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-10-25 03:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 58dc06b68b..ef4fa7144f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23263,6 +23263,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23302,6 +23303,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Oct_25_13_04_53_2024_648)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v23-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v23 6/8] Row pattern recognition patch (docs).
@ 2024-10-25 03:56 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-10-25 03:56 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 58dc06b68b..ef4fa7144f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23263,6 +23263,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23302,6 +23303,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Fri_Oct_25_13_04_53_2024_648)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v23-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v24 6/8] Row pattern recognition patch (docs).
@ 2024-12-19 06:06 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Dec_19_15_19_50_2024_894)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v24-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v24 6/8] Row pattern recognition patch (docs).
@ 2024-12-19 06:06 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Dec_19_15_19_50_2024_894)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v24-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v24 6/8] Row pattern recognition patch (docs).
@ 2024-12-19 06:06 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Thu_Dec_19_15_19_50_2024_894)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v24-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v25 6/9] Row pattern recognition patch (docs).
@ 2024-12-21 06:19 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-21 06:19 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Dec_21_18_20_04_2024_526)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v25-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v25 6/9] Row pattern recognition patch (docs).
@ 2024-12-21 06:19 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-21 06:19 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Dec_21_18_20_04_2024_526)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v25-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v25 6/9] Row pattern recognition patch (docs).
@ 2024-12-21 06:19 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-21 06:19 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Sat_Dec_21_18_20_04_2024_526)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v25-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v26 6/9] Row pattern recognition patch (docs).
@ 2024-12-30 12:44 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-30 12:44 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Dec_30_22_37_18_2024_171)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v26-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v26 6/9] Row pattern recognition patch (docs).
@ 2024-12-30 12:44 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-30 12:44 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Dec_30_22_37_18_2024_171)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v26-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v26 6/9] Row pattern recognition patch (docs).
@ 2024-12-30 12:44 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-30 12:44 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Mon_Dec_30_22_37_18_2024_171)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v26-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v27 6/9] Row pattern recognition patch (docs).
@ 2024-12-30 23:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-30 23:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Dec_31_08_57_07_2024_963)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v27-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v27 6/9] Row pattern recognition patch (docs).
@ 2024-12-30 23:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-30 23:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Dec_31_08_57_07_2024_963)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v27-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v27 6/9] Row pattern recognition patch (docs).
@ 2024-12-30 23:53 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Tatsuo Ishii @ 2024-12-30 23:53 UTC (permalink / raw)
---
doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++
doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++-
3 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..b0b1d1c51e 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,88 @@ WHERE pos < 3;
<literal>rank</literal> less than 3.
</para>
+ <para>
+ Row pattern common syntax can be used to perform row pattern recognition
+ in a query. The row pattern common syntax includes two sub
+ clauses: <literal>DEFINE</literal>
+ and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines
+ definition variables along with an expression. The expression must be a
+ logical expression, which means it must
+ return <literal>TRUE</literal>, <literal>FALSE</literal>
+ or <literal>NULL</literal>. The expression may comprise column references
+ and functions. Window functions, aggregate functions and subqueries are
+ not allowed. An example of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+</programlisting>
+
+ Note that <function>PREV</function> returns the price column in the
+ previous row if it's called in a context of row pattern recognition. Thus in
+ the second line the definition variable "UP" is <literal>TRUE</literal>
+ when the price column in the current row is greater than the price column
+ in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+ the price column in the current row is lower than the price column in the
+ previous row.
+ </para>
+ <para>
+ Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+ used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+ certain conditions. For example following <literal>PATTERN</literal>
+ defines that a row starts with the condition "LOWPRICE", then one or more
+ rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that
+ "+" means one or more matches. Also you can use "*", which means zero or
+ more matches. If a sequence of rows which satisfies the PATTERN is found,
+ in the starting row of the sequence of rows all window functions and
+ aggregates are shown in the target list. Note that aggregations only look
+ into the matched rows, rather than whole frame. On the second or
+ subsequent rows all window functions are NULL. Aggregates are NULL or 0
+ (count case) depending on its aggregation definition. For rows that do not
+ match on the PATTERN, all window functions and aggregates are shown AS
+ NULL too, except count showing 0. This is because the rows do not match,
+ thus they are in an empty frame. Example of a <literal>SELECT</literal>
+ using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause
+ is as follows.
+
+<programlisting>
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ max(price) OVER w,
+ count(price) OVER w
+FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+</programlisting>
+<screen>
+ company | tdate | price | first_value | max | count
+----------+------------+-------+-------------+-----+-------
+ company1 | 2023-07-01 | 100 | 100 | 200 | 4
+ company1 | 2023-07-02 | 200 | | | 0
+ company1 | 2023-07-03 | 150 | | | 0
+ company1 | 2023-07-04 | 140 | | | 0
+ company1 | 2023-07-05 | 150 | | | 0
+ company1 | 2023-07-06 | 90 | 90 | 130 | 4
+ company1 | 2023-07-07 | 110 | | | 0
+ company1 | 2023-07-08 | 130 | | | 0
+ company1 | 2023-07-09 | 120 | | | 0
+ company1 | 2023-07-10 | 130 | | | 0
+(10 rows)
+</screen>
+ </para>
+
<para>
When a query involves multiple window functions, it is possible to write
out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 47370e581a..17a38c4046 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable;
returns <literal>NULL</literal> if there is no such row.
</para></entry>
</row>
+
</tbody>
</tgroup>
</table>
@@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable;
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ Row pattern recognition navigation functions are listed in
+ <xref linkend="functions-rpr-navigation-table"/>. These functions
+ can be used to describe DEFINE clause of Row pattern recognition.
+ </para>
+
+ <table id="functions-rpr-navigation-table">
+ <title>Row Pattern Navigation Functions</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ Function
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>prev</primary>
+ </indexterm>
+ <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the previous row;
+ returns NULL if there is no previous row in the window frame.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>next</primary>
+ </indexterm>
+ <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <returnvalue>anyelement</returnvalue>
+ </para>
+ <para>
+ Returns the column value at the next row;
+ returns NULL if there is no next row in the window frame.
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+
<note>
<para>
The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index d7089eac0b..7e1c9989ba 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
The <replaceable class="parameter">frame_clause</replaceable> can be one of
<synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
</synopsis>
where <replaceable>frame_start</replaceable>
@@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS
a given peer group will be in the frame or excluded from it.
</para>
+ <para>
+ The
+ optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ defines the <firstterm>row pattern recognition condition</firstterm> for
+ this
+ window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+ includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+ ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+ how to proceed to next row position after a match
+ found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+ default) next row position is next to the last row of previous match. On
+ the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+ row position is always next to the last row of previous
+ match. <literal>DEFINE</literal> defines definition variables along with a
+ boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+ that satisfies certain conditions using variables defined
+ in <literal>DEFINE</literal> clause. If the variable is not defined in
+ the <literal>DEFINE</literal> clause, it is implicitly assumed
+ following is defined in the <literal>DEFINE</literal> clause.
+
+<synopsis>
+<literal>variable_name</literal> AS TRUE
+</synopsis>
+
+ Note that the maximu number of variables defined
+ in <literal>DEFINE</literal> clause is 26.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>
+ </para>
+
<para>
The purpose of a <literal>WINDOW</literal> clause is to specify the
behavior of <firstterm>window functions</firstterm> appearing in the query's
--
2.25.1
----Next_Part(Tue_Dec_31_08_57_07_2024_963)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v27-0007-Row-pattern-recognition-patch-tests.patch"
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2] remove #include <math.h> where not needed
@ 2026-01-15 13:33 Álvaro Herrera <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Álvaro Herrera @ 2026-01-15 13:33 UTC (permalink / raw)
Discussion: https://postgr.es/m/[email protected]
---
contrib/btree_gist/btree_numeric.c | 1 -
contrib/btree_gist/btree_utils_var.c | 1 -
contrib/intarray/_intbig_gist.c | 2 --
contrib/ltree/_ltree_gist.c | 2 --
contrib/seg/segparse.y | 1 -
src/backend/access/heap/vacuumlazy.c | 2 --
src/backend/access/transam/xlogrecovery.c | 1 -
src/backend/access/transam/xlogwait.c | 1 -
src/backend/commands/define.c | 1 -
src/backend/executor/nodeBitmapHeapscan.c | 2 --
src/backend/executor/nodeSubplan.c | 2 --
src/backend/lib/knapsack.c | 1 -
src/backend/nodes/readfuncs.c | 2 --
src/backend/optimizer/geqo/geqo_eval.c | 1 -
src/backend/optimizer/geqo/geqo_pool.c | 1 -
src/backend/optimizer/path/indxpath.c | 2 --
src/backend/optimizer/path/joinpath.c | 2 --
src/backend/optimizer/plan/createplan.c | 2 --
src/backend/optimizer/util/pathnode.c | 2 --
src/backend/statistics/mcv.c | 2 --
src/backend/utils/adt/numutils.c | 1 -
src/backend/utils/adt/tid.c | 1 -
src/common/binaryheap.c | 2 --
src/include/utils/date.h | 2 --
24 files changed, 37 deletions(-)
diff --git a/contrib/btree_gist/btree_numeric.c b/contrib/btree_gist/btree_numeric.c
index 052f27b0794..7ca097abb74 100644
--- a/contrib/btree_gist/btree_numeric.c
+++ b/contrib/btree_gist/btree_numeric.c
@@ -3,7 +3,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <float.h>
#include "btree_gist.h"
diff --git a/contrib/btree_gist/btree_utils_var.c b/contrib/btree_gist/btree_utils_var.c
index 40e06ae4908..6847e4e54d5 100644
--- a/contrib/btree_gist/btree_utils_var.c
+++ b/contrib/btree_gist/btree_utils_var.c
@@ -3,7 +3,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include <float.h>
diff --git a/contrib/intarray/_intbig_gist.c b/contrib/intarray/_intbig_gist.c
index 0afa8a73b68..6d6ff7413f9 100644
--- a/contrib/intarray/_intbig_gist.c
+++ b/contrib/intarray/_intbig_gist.c
@@ -3,8 +3,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "_int.h"
#include "access/gist.h"
#include "access/reloptions.h"
diff --git a/contrib/ltree/_ltree_gist.c b/contrib/ltree/_ltree_gist.c
index ceb92a6304d..6383b37e53f 100644
--- a/contrib/ltree/_ltree_gist.c
+++ b/contrib/ltree/_ltree_gist.c
@@ -7,8 +7,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/gist.h"
#include "access/reloptions.h"
#include "access/stratnum.h"
diff --git a/contrib/seg/segparse.y b/contrib/seg/segparse.y
index 0358ddb182c..a3dbd0cdbd6 100644
--- a/contrib/seg/segparse.y
+++ b/contrib/seg/segparse.y
@@ -4,7 +4,6 @@
#include "postgres.h"
#include <float.h>
-#include <math.h>
#include "fmgr.h"
#include "nodes/miscnodes.h"
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 2086a577199..1fcb212ab3d 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -129,8 +129,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 0b5f871abe7..117d8d8bb6b 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -25,7 +25,6 @@
#include "postgres.h"
#include <ctype.h>
-#include <math.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/time.h>
diff --git a/src/backend/access/transam/xlogwait.c b/src/backend/access/transam/xlogwait.c
index cab7e5082dc..d286ff63123 100644
--- a/src/backend/access/transam/xlogwait.c
+++ b/src/backend/access/transam/xlogwait.c
@@ -47,7 +47,6 @@
#include "postgres.h"
#include <float.h>
-#include <math.h>
#include "access/xlog.h"
#include "access/xlogrecovery.h"
diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c
index 8313431397f..4172cc9bacb 100644
--- a/src/backend/commands/define.c
+++ b/src/backend/commands/define.c
@@ -20,7 +20,6 @@
#include "postgres.h"
#include <ctype.h>
-#include <math.h>
#include "catalog/namespace.h"
#include "commands/defrem.h"
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 2c68327cb29..c68c26cbf38 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -35,8 +35,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/relscan.h"
#include "access/tableam.h"
#include "access/visibilitymap.h"
diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c
index 5e510c73926..8285c7101c2 100644
--- a/src/backend/executor/nodeSubplan.c
+++ b/src/backend/executor/nodeSubplan.c
@@ -26,8 +26,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/htup_details.h"
#include "executor/executor.h"
#include "executor/nodeSubplan.h"
diff --git a/src/backend/lib/knapsack.c b/src/backend/lib/knapsack.c
index 1a770b907ec..586f1881fd5 100644
--- a/src/backend/lib/knapsack.c
+++ b/src/backend/lib/knapsack.c
@@ -24,7 +24,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include "lib/knapsack.h"
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index c11728c0f17..981ab9c34ef 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -26,8 +26,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "miscadmin.h"
#include "nodes/bitmapset.h"
#include "nodes/readfuncs.h"
diff --git a/src/backend/optimizer/geqo/geqo_eval.c b/src/backend/optimizer/geqo/geqo_eval.c
index db2332e2364..56ad3df98fa 100644
--- a/src/backend/optimizer/geqo/geqo_eval.c
+++ b/src/backend/optimizer/geqo/geqo_eval.c
@@ -23,7 +23,6 @@
#include <float.h>
#include <limits.h>
-#include <math.h>
#include "optimizer/geqo.h"
#include "optimizer/joininfo.h"
diff --git a/src/backend/optimizer/geqo/geqo_pool.c b/src/backend/optimizer/geqo/geqo_pool.c
index fc43406d0c1..f330c739d3d 100644
--- a/src/backend/optimizer/geqo/geqo_pool.c
+++ b/src/backend/optimizer/geqo/geqo_pool.c
@@ -25,7 +25,6 @@
#include <float.h>
#include <limits.h>
-#include <math.h>
#include "optimizer/geqo_copy.h"
#include "optimizer/geqo_pool.h"
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 51b9d6677d3..29cb60d6b35 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -15,8 +15,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/stratnum.h"
#include "access/sysattr.h"
#include "access/transam.h"
diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c
index 7a247493a39..36973eab3be 100644
--- a/src/backend/optimizer/path/joinpath.c
+++ b/src/backend/optimizer/path/joinpath.c
@@ -14,8 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "executor/executor.h"
#include "foreign/fdwapi.h"
#include "nodes/nodeFuncs.h"
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index af41ca69929..eb4806b084a 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -16,8 +16,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/sysattr.h"
#include "catalog/pg_class.h"
#include "foreign/fdwapi.h"
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index 2e9becf3116..0f12421bac0 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -14,8 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/htup_details.h"
#include "executor/nodeSetOp.h"
#include "foreign/fdwapi.h"
diff --git a/src/backend/statistics/mcv.c b/src/backend/statistics/mcv.c
index 9749871b18e..e5ac422c1b4 100644
--- a/src/backend/statistics/mcv.c
+++ b/src/backend/statistics/mcv.c
@@ -14,8 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/htup_details.h"
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_statistic_ext_data.h"
diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c
index b35e381b0be..47c2e21e6b3 100644
--- a/src/backend/utils/adt/numutils.c
+++ b/src/backend/utils/adt/numutils.c
@@ -14,7 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include <ctype.h>
diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
index c627b385eec..07248b69e57 100644
--- a/src/backend/utils/adt/tid.c
+++ b/src/backend/utils/adt/tid.c
@@ -17,7 +17,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include "access/sysattr.h"
diff --git a/src/common/binaryheap.c b/src/common/binaryheap.c
index d2be882e65c..78823ff00f8 100644
--- a/src/common/binaryheap.c
+++ b/src/common/binaryheap.c
@@ -17,8 +17,6 @@
#include "postgres.h"
#endif
-#include <math.h>
-
#ifdef FRONTEND
#include "common/logging.h"
#endif
diff --git a/src/include/utils/date.h b/src/include/utils/date.h
index 1c5dfc94ee6..6063810891e 100644
--- a/src/include/utils/date.h
+++ b/src/include/utils/date.h
@@ -14,8 +14,6 @@
#ifndef DATE_H
#define DATE_H
-#include <math.h>
-
#include "datatype/timestamp.h"
#include "fmgr.h"
#include "pgtime.h"
--
2.47.3
--uzfvjzgwtlw4oib4--
^ permalink raw reply [nested|flat] 118+ messages in thread
* [PATCH v2] remove #include <math.h> where not needed
@ 2026-01-15 13:33 Álvaro Herrera <[email protected]>
0 siblings, 0 replies; 118+ messages in thread
From: Álvaro Herrera @ 2026-01-15 13:33 UTC (permalink / raw)
Discussion: https://postgr.es/m/[email protected]
---
contrib/btree_gist/btree_numeric.c | 1 -
contrib/btree_gist/btree_utils_var.c | 1 -
contrib/intarray/_intbig_gist.c | 2 --
contrib/ltree/_ltree_gist.c | 2 --
contrib/seg/segparse.y | 1 -
src/backend/access/heap/vacuumlazy.c | 2 --
src/backend/access/transam/xlogrecovery.c | 1 -
src/backend/access/transam/xlogwait.c | 1 -
src/backend/commands/define.c | 1 -
src/backend/executor/nodeBitmapHeapscan.c | 2 --
src/backend/executor/nodeSubplan.c | 2 --
src/backend/lib/knapsack.c | 1 -
src/backend/nodes/readfuncs.c | 2 --
src/backend/optimizer/geqo/geqo_eval.c | 1 -
src/backend/optimizer/geqo/geqo_pool.c | 1 -
src/backend/optimizer/path/indxpath.c | 2 --
src/backend/optimizer/path/joinpath.c | 2 --
src/backend/optimizer/plan/createplan.c | 2 --
src/backend/optimizer/util/pathnode.c | 2 --
src/backend/statistics/mcv.c | 2 --
src/backend/utils/adt/numutils.c | 1 -
src/backend/utils/adt/tid.c | 1 -
src/common/binaryheap.c | 2 --
src/include/utils/date.h | 2 --
24 files changed, 37 deletions(-)
diff --git a/contrib/btree_gist/btree_numeric.c b/contrib/btree_gist/btree_numeric.c
index 052f27b0794..7ca097abb74 100644
--- a/contrib/btree_gist/btree_numeric.c
+++ b/contrib/btree_gist/btree_numeric.c
@@ -3,7 +3,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <float.h>
#include "btree_gist.h"
diff --git a/contrib/btree_gist/btree_utils_var.c b/contrib/btree_gist/btree_utils_var.c
index 40e06ae4908..6847e4e54d5 100644
--- a/contrib/btree_gist/btree_utils_var.c
+++ b/contrib/btree_gist/btree_utils_var.c
@@ -3,7 +3,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include <float.h>
diff --git a/contrib/intarray/_intbig_gist.c b/contrib/intarray/_intbig_gist.c
index 0afa8a73b68..6d6ff7413f9 100644
--- a/contrib/intarray/_intbig_gist.c
+++ b/contrib/intarray/_intbig_gist.c
@@ -3,8 +3,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "_int.h"
#include "access/gist.h"
#include "access/reloptions.h"
diff --git a/contrib/ltree/_ltree_gist.c b/contrib/ltree/_ltree_gist.c
index ceb92a6304d..6383b37e53f 100644
--- a/contrib/ltree/_ltree_gist.c
+++ b/contrib/ltree/_ltree_gist.c
@@ -7,8 +7,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/gist.h"
#include "access/reloptions.h"
#include "access/stratnum.h"
diff --git a/contrib/seg/segparse.y b/contrib/seg/segparse.y
index 0358ddb182c..a3dbd0cdbd6 100644
--- a/contrib/seg/segparse.y
+++ b/contrib/seg/segparse.y
@@ -4,7 +4,6 @@
#include "postgres.h"
#include <float.h>
-#include <math.h>
#include "fmgr.h"
#include "nodes/miscnodes.h"
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 2086a577199..1fcb212ab3d 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -129,8 +129,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 0b5f871abe7..117d8d8bb6b 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -25,7 +25,6 @@
#include "postgres.h"
#include <ctype.h>
-#include <math.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/time.h>
diff --git a/src/backend/access/transam/xlogwait.c b/src/backend/access/transam/xlogwait.c
index cab7e5082dc..d286ff63123 100644
--- a/src/backend/access/transam/xlogwait.c
+++ b/src/backend/access/transam/xlogwait.c
@@ -47,7 +47,6 @@
#include "postgres.h"
#include <float.h>
-#include <math.h>
#include "access/xlog.h"
#include "access/xlogrecovery.h"
diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c
index 8313431397f..4172cc9bacb 100644
--- a/src/backend/commands/define.c
+++ b/src/backend/commands/define.c
@@ -20,7 +20,6 @@
#include "postgres.h"
#include <ctype.h>
-#include <math.h>
#include "catalog/namespace.h"
#include "commands/defrem.h"
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 2c68327cb29..c68c26cbf38 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -35,8 +35,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/relscan.h"
#include "access/tableam.h"
#include "access/visibilitymap.h"
diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c
index 5e510c73926..8285c7101c2 100644
--- a/src/backend/executor/nodeSubplan.c
+++ b/src/backend/executor/nodeSubplan.c
@@ -26,8 +26,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/htup_details.h"
#include "executor/executor.h"
#include "executor/nodeSubplan.h"
diff --git a/src/backend/lib/knapsack.c b/src/backend/lib/knapsack.c
index 1a770b907ec..586f1881fd5 100644
--- a/src/backend/lib/knapsack.c
+++ b/src/backend/lib/knapsack.c
@@ -24,7 +24,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include "lib/knapsack.h"
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index c11728c0f17..981ab9c34ef 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -26,8 +26,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "miscadmin.h"
#include "nodes/bitmapset.h"
#include "nodes/readfuncs.h"
diff --git a/src/backend/optimizer/geqo/geqo_eval.c b/src/backend/optimizer/geqo/geqo_eval.c
index db2332e2364..56ad3df98fa 100644
--- a/src/backend/optimizer/geqo/geqo_eval.c
+++ b/src/backend/optimizer/geqo/geqo_eval.c
@@ -23,7 +23,6 @@
#include <float.h>
#include <limits.h>
-#include <math.h>
#include "optimizer/geqo.h"
#include "optimizer/joininfo.h"
diff --git a/src/backend/optimizer/geqo/geqo_pool.c b/src/backend/optimizer/geqo/geqo_pool.c
index fc43406d0c1..f330c739d3d 100644
--- a/src/backend/optimizer/geqo/geqo_pool.c
+++ b/src/backend/optimizer/geqo/geqo_pool.c
@@ -25,7 +25,6 @@
#include <float.h>
#include <limits.h>
-#include <math.h>
#include "optimizer/geqo_copy.h"
#include "optimizer/geqo_pool.h"
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 51b9d6677d3..29cb60d6b35 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -15,8 +15,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/stratnum.h"
#include "access/sysattr.h"
#include "access/transam.h"
diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c
index 7a247493a39..36973eab3be 100644
--- a/src/backend/optimizer/path/joinpath.c
+++ b/src/backend/optimizer/path/joinpath.c
@@ -14,8 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "executor/executor.h"
#include "foreign/fdwapi.h"
#include "nodes/nodeFuncs.h"
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index af41ca69929..eb4806b084a 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -16,8 +16,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/sysattr.h"
#include "catalog/pg_class.h"
#include "foreign/fdwapi.h"
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index 2e9becf3116..0f12421bac0 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -14,8 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/htup_details.h"
#include "executor/nodeSetOp.h"
#include "foreign/fdwapi.h"
diff --git a/src/backend/statistics/mcv.c b/src/backend/statistics/mcv.c
index 9749871b18e..e5ac422c1b4 100644
--- a/src/backend/statistics/mcv.c
+++ b/src/backend/statistics/mcv.c
@@ -14,8 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
-
#include "access/htup_details.h"
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_statistic_ext_data.h"
diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c
index b35e381b0be..47c2e21e6b3 100644
--- a/src/backend/utils/adt/numutils.c
+++ b/src/backend/utils/adt/numutils.c
@@ -14,7 +14,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include <ctype.h>
diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
index c627b385eec..07248b69e57 100644
--- a/src/backend/utils/adt/tid.c
+++ b/src/backend/utils/adt/tid.c
@@ -17,7 +17,6 @@
*/
#include "postgres.h"
-#include <math.h>
#include <limits.h>
#include "access/sysattr.h"
diff --git a/src/common/binaryheap.c b/src/common/binaryheap.c
index d2be882e65c..78823ff00f8 100644
--- a/src/common/binaryheap.c
+++ b/src/common/binaryheap.c
@@ -17,8 +17,6 @@
#include "postgres.h"
#endif
-#include <math.h>
-
#ifdef FRONTEND
#include "common/logging.h"
#endif
diff --git a/src/include/utils/date.h b/src/include/utils/date.h
index 1c5dfc94ee6..6063810891e 100644
--- a/src/include/utils/date.h
+++ b/src/include/utils/date.h
@@ -14,8 +14,6 @@
#ifndef DATE_H
#define DATE_H
-#include <math.h>
-
#include "datatype/timestamp.h"
#include "fmgr.h"
#include "pgtime.h"
--
2.47.3
--uzfvjzgwtlw4oib4--
^ permalink raw reply [nested|flat] 118+ messages in thread
end of thread, other threads:[~2026-01-15 13:33 UTC | newest]
Thread overview: 118+ messages (download: mbox mbox.gz follow: Atom feed)
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2018-06-18 12:34 [PATCH 3/8] Add rewrite rules and tupdesc flags Ildus Kurbangaliev <[email protected]>
2019-03-07 20:49 [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops Nikita Glukhov <[email protected]>
2019-03-07 20:49 [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops Nikita Glukhov <[email protected]>
2019-03-07 20:49 [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops Nikita Glukhov <[email protected]>
2022-02-24 08:27 Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Kyotaro Horiguchi <[email protected]>
2022-02-25 21:28 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Imseih (AWS), Sami <[email protected]>
2022-03-07 20:34 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Imseih (AWS), Sami <[email protected]>
2022-03-23 17:24 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion [email protected] <[email protected]>
2022-05-26 19:57 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Imseih (AWS), Sami <[email protected]>
2022-05-27 01:59 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Kyotaro Horiguchi <[email protected]>
2022-05-27 02:01 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Imseih (AWS), Sami <[email protected]>
2022-05-27 06:37 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Kyotaro Horiguchi <[email protected]>
2022-05-27 19:01 ` Re: [BUG] Panic due to incorrect missingContrecPtr after promotion Imseih (AWS), Sami <[email protected]>
2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-11-08 06:57 [PATCH v11 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-11-08 06:57 [PATCH v11 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-11-08 06:57 [PATCH v11 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-12-04 11:23 [PATCH v12 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-12-04 11:23 [PATCH v12 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2023-12-04 11:23 [PATCH v12 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-01-22 09:45 [PATCH v13 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-01-22 09:45 [PATCH v13 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-01-22 09:45 [PATCH v13 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-02-28 13:59 [PATCH v14 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-02-28 13:59 [PATCH v14 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-02-28 13:59 [PATCH v14 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-04-12 06:49 [PATCH v16 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-04-12 06:49 [PATCH v16 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-04-12 06:49 [PATCH v16 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-04-28 11:00 [PATCH v17 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-04-28 11:00 [PATCH v17 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-04-28 11:00 [PATCH v17 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-14 23:26 [PATCH v19 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-14 23:26 [PATCH v19 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-14 23:26 [PATCH v19 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-24 02:26 [PATCH v20 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-24 02:26 [PATCH v20 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-05-24 02:26 [PATCH v20 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-08-26 04:32 [PATCH v21 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-08-26 04:32 [PATCH v21 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-08-26 04:32 [PATCH v21 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-09-19 04:48 [PATCH v22 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-09-19 04:48 [PATCH v22 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-09-19 04:48 [PATCH v22 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-10-25 03:56 [PATCH v23 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-10-25 03:56 [PATCH v23 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-10-25 03:56 [PATCH v23 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-19 06:06 [PATCH v24 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-19 06:06 [PATCH v24 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-19 06:06 [PATCH v24 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-21 06:19 [PATCH v25 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-21 06:19 [PATCH v25 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-21 06:19 [PATCH v25 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-30 12:44 [PATCH v26 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-30 12:44 [PATCH v26 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-30 12:44 [PATCH v26 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-30 23:53 [PATCH v27 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-30 23:53 [PATCH v27 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2024-12-30 23:53 [PATCH v27 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
2026-01-15 13:33 [PATCH v2] remove #include <math.h> where not needed Álvaro Herrera <[email protected]>
2026-01-15 13:33 [PATCH v2] remove #include <math.h> where not needed Álvaro Herrera <[email protected]>
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