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help / color / mirror / Atom feedFrom: Tatsuo Ishii <[email protected]>
Subject: [PATCH v3 4/7] Row pattern recognition patch (executor).
Date: Wed, 26 Jul 2023 19:49:09 +0900
---
src/backend/executor/nodeWindowAgg.c | 701 ++++++++++++++++++++++++++-
src/backend/utils/adt/windowfuncs.c | 38 +-
src/include/catalog/pg_proc.dat | 6 +
src/include/nodes/execnodes.h | 18 +
src/include/windowapi.h | 8 +
5 files changed, 758 insertions(+), 13 deletions(-)
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 310ac23e3a..0586bf57d6 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -36,6 +36,7 @@
#include "access/htup_details.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_aggregate.h"
+#include "catalog/pg_collation_d.h"
#include "catalog/pg_proc.h"
#include "executor/executor.h"
#include "executor/nodeWindowAgg.h"
@@ -48,6 +49,7 @@
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
+#include "utils/fmgroids.h"
#include "utils/expandeddatum.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
@@ -159,6 +161,14 @@ typedef struct WindowStatePerAggData
bool restart; /* need to restart this agg in this cycle? */
} WindowStatePerAggData;
+/*
+ * Map between Var attno in a target list and the parsed attno.
+ */
+typedef struct AttnoMap {
+ List *attno; /* att number in target list (list of AttNumber) */
+ List *attnosyn; /* parsed att number (list of AttNumber) */
+} AttnoMap;
+
static void initialize_windowaggregate(WindowAggState *winstate,
WindowStatePerFunc perfuncstate,
WindowStatePerAgg peraggstate);
@@ -182,8 +192,9 @@ static void begin_partition(WindowAggState *winstate);
static void spool_tuples(WindowAggState *winstate, int64 pos);
static void release_partition(WindowAggState *winstate);
-static int row_is_in_frame(WindowAggState *winstate, int64 pos,
+static int row_is_in_frame(WindowAggState *winstate, int64 pos,
TupleTableSlot *slot);
+
static void update_frameheadpos(WindowAggState *winstate);
static void update_frametailpos(WindowAggState *winstate);
static void update_grouptailpos(WindowAggState *winstate);
@@ -195,9 +206,19 @@ static Datum GetAggInitVal(Datum textInitVal, Oid transtype);
static bool are_peers(WindowAggState *winstate, TupleTableSlot *slot1,
TupleTableSlot *slot2);
-static bool window_gettupleslot(WindowObject winobj, int64 pos,
- TupleTableSlot *slot);
+static void attno_map(Node *node, AttnoMap *map);
+static bool attno_map_walker(Node *node, void *context);
+static int row_is_in_reduced_frame(WindowObject winobj, int64 pos);
+
+static int64 evaluate_pattern(WindowObject winobj, int64 current_pos,
+ char *vname, StringInfo encoded_str, bool *result);
+
+static bool get_slots(WindowObject winobj, int64 current_pos);
+
+static int search_str_set(char *pattern, StringInfo *str_set, int set_size);
+static void search_str_set_recurse(char *pattern, StringInfo *str_set, int set_size, int set_index,
+ char *encoded_str, int *resultlen);
/*
* initialize_windowaggregate
@@ -673,6 +694,9 @@ eval_windowaggregates(WindowAggState *winstate)
WindowObject agg_winobj;
TupleTableSlot *agg_row_slot;
TupleTableSlot *temp_slot;
+ bool reduced_frame_set;
+ bool check_reduced_frame;
+ int num_rows_in_reduced_frame;
numaggs = winstate->numaggs;
if (numaggs == 0)
@@ -790,6 +814,7 @@ eval_windowaggregates(WindowAggState *winstate)
(winstate->frameOptions & FRAMEOPTION_EXCLUSION) ||
winstate->aggregatedupto <= winstate->frameheadpos)
{
+ elog(DEBUG1, "peraggstate->restart is set");
peraggstate->restart = true;
numaggs_restart++;
}
@@ -861,8 +886,10 @@ eval_windowaggregates(WindowAggState *winstate)
* If we created a mark pointer for aggregates, keep it pushed up to frame
* head, so that tuplestore can discard unnecessary rows.
*/
+#ifdef NOT_USED
if (agg_winobj->markptr >= 0)
WinSetMarkPosition(agg_winobj, winstate->frameheadpos);
+#endif
/*
* Now restart the aggregates that require it.
@@ -919,6 +946,10 @@ eval_windowaggregates(WindowAggState *winstate)
ExecClearTuple(agg_row_slot);
}
+ reduced_frame_set = false;
+ check_reduced_frame = false;
+ num_rows_in_reduced_frame = 0;
+
/*
* Advance until we reach a row not in frame (or end of partition).
*
@@ -930,12 +961,18 @@ eval_windowaggregates(WindowAggState *winstate)
{
int ret;
+ elog(DEBUG1, "===== loop in frame starts: " INT64_FORMAT, winstate->aggregatedupto);
+
/* Fetch next row if we didn't already */
if (TupIsNull(agg_row_slot))
{
if (!window_gettupleslot(agg_winobj, winstate->aggregatedupto,
agg_row_slot))
+ {
+ if (check_reduced_frame)
+ winstate->aggregatedupto--;
break; /* must be end of partition */
+ }
}
/*
@@ -944,10 +981,47 @@ eval_windowaggregates(WindowAggState *winstate)
*/
ret = row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot);
if (ret < 0)
+ {
+ if (winstate->patternVariableList != NIL && check_reduced_frame)
+ winstate->aggregatedupto--;
break;
+ }
if (ret == 0)
goto next_tuple;
+ if (winstate->patternVariableList != NIL)
+ {
+ if (!reduced_frame_set)
+ {
+ num_rows_in_reduced_frame = row_is_in_reduced_frame(winstate->agg_winobj, winstate->aggregatedupto);
+ reduced_frame_set = true;
+ elog(DEBUG1, "set num_rows_in_reduced_frame: %d pos: " INT64_FORMAT,
+ num_rows_in_reduced_frame, winstate->aggregatedupto);
+
+ if (num_rows_in_reduced_frame <= 0)
+ break;
+
+ else if (num_rows_in_reduced_frame > 0)
+ check_reduced_frame = true;
+ }
+
+ if (check_reduced_frame)
+ {
+ elog(DEBUG1, "decrease num_rows_in_reduced_frame: %d pos: " INT64_FORMAT,
+ num_rows_in_reduced_frame, winstate->aggregatedupto);
+ num_rows_in_reduced_frame--;
+ if (num_rows_in_reduced_frame < 0)
+ {
+ /*
+ * No more rows remain in the reduced frame. Finish
+ * accumulating row into the aggregates.
+ */
+ winstate->aggregatedupto--;
+ break;
+ }
+ }
+ }
+
/* Set tuple context for evaluation of aggregate arguments */
winstate->tmpcontext->ecxt_outertuple = agg_row_slot;
@@ -976,6 +1050,8 @@ next_tuple:
ExecClearTuple(agg_row_slot);
}
+ elog(DEBUG1, "===== break loop in frame starts: " INT64_FORMAT, winstate->aggregatedupto);
+
/* The frame's end is not supposed to move backwards, ever */
Assert(aggregatedupto_nonrestarted <= winstate->aggregatedupto);
@@ -2053,6 +2129,8 @@ ExecWindowAgg(PlanState *pstate)
CHECK_FOR_INTERRUPTS();
+ elog(DEBUG1, "ExecWindowAgg called. pos: " INT64_FORMAT , winstate->currentpos);
+
if (winstate->status == WINDOWAGG_DONE)
return NULL;
@@ -2388,6 +2466,12 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
TupleDesc scanDesc;
ListCell *l;
+ TargetEntry *te;
+ Expr *expr;
+ Var *var;
+ int nargs;
+ AttnoMap attnomap;
+
/* check for unsupported flags */
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
@@ -2483,6 +2567,16 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
winstate->temp_slot_2 = ExecInitExtraTupleSlot(estate, scanDesc,
&TTSOpsMinimalTuple);
+ winstate->prev_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsMinimalTuple);
+
+ winstate->next_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsMinimalTuple);
+
+ winstate->null_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsMinimalTuple);
+ winstate->null_slot = ExecStoreAllNullTuple(winstate->null_slot);
+
/*
* create frame head and tail slots only if needed (must create slots in
* exactly the same cases that update_frameheadpos and update_frametailpos
@@ -2667,6 +2761,69 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
winstate->inRangeAsc = node->inRangeAsc;
winstate->inRangeNullsFirst = node->inRangeNullsFirst;
+ /* Set up SKIP TO type */
+ winstate->rpSkipTo = node->rpSkipTo;
+ /* Set up row pattern recognition PATTERN clause */
+ winstate->patternVariableList = node->patternVariable;
+ winstate->patternRegexpList = node->patternRegexp;
+
+ /* Set up row pattern recognition DEFINE clause */
+
+ /*
+ * Collect mapping between varattno and varattnosyn in the targetlist.
+ * XXX: For now we only check RPR's argument. Eventually we have to
+ * recurse the targetlist to find out all mappings in Var nodes.
+ */
+ attnomap.attno = NIL;
+ attnomap.attnosyn = NIL;
+
+ foreach (l, node->plan.targetlist)
+ {
+ te = lfirst(l);
+ if (IsA(te->expr, WindowFunc))
+ {
+ WindowFunc *func = (WindowFunc *)te->expr;
+
+ /* sanity check */
+ nargs = list_length(func->args);
+ if (nargs != 1)
+ continue;
+
+ expr = (Expr *) lfirst(list_head(func->args));
+ if (!IsA(expr, Var))
+ continue;
+
+ var = (Var *)expr;
+ elog(DEBUG1, "resname: %s varattno: %d varattnosyn: %d",
+ te->resname, var->varattno, var->varattnosyn);
+ attnomap.attno = lappend_int(attnomap.attno, var->varattno);
+ attnomap.attnosyn = lappend_int(attnomap.attnosyn, var->varattnosyn);
+ }
+ }
+
+ winstate->defineVariableList = NIL;
+ winstate->defineClauseList = NIL;
+ if (node->defineClause != NIL)
+ {
+ foreach(l, node->defineClause)
+ {
+ char *name;
+ ExprState *exps;
+
+ te = lfirst(l);
+ name = te->resname;
+ expr = te->expr;
+
+ elog(DEBUG1, "defineVariable name: %s", name);
+ winstate->defineVariableList = lappend(winstate->defineVariableList,
+ makeString(pstrdup(name)));
+ /* tweak expr so that it referes to outer slot */
+ attno_map((Node *)expr, &attnomap);
+ exps = ExecInitExpr(expr, (PlanState *) winstate);
+ winstate->defineClauseList = lappend(winstate->defineClauseList, exps);
+ }
+ }
+
winstate->all_first = true;
winstate->partition_spooled = false;
winstate->more_partitions = false;
@@ -2674,6 +2831,77 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
return winstate;
}
+/*
+ * Rewrite Var node's varattno to the varattno which is used in the target
+ * list using AttnoMap. We also rewrite varno so that it sees outer tuple
+ * (PREV) or inner tuple (NEXT).
+ */
+static void
+attno_map(Node *node, AttnoMap *map)
+{
+ (void) expression_tree_walker(node, attno_map_walker, (void *) map);
+}
+
+static bool
+attno_map_walker(Node *node, void *context)
+{
+ FuncExpr *func;
+ int nargs;
+ Expr *expr;
+ Var *var;
+ AttnoMap *attnomap;
+ ListCell *lc1, *lc2;
+
+ if (node == NULL)
+ return false;
+
+ attnomap = (AttnoMap *) context;
+
+ if (IsA(node, FuncExpr))
+ {
+ func = (FuncExpr *)node;
+
+ if (func->funcid == F_PREV || func->funcid == F_NEXT)
+ {
+ /* sanity check */
+ nargs = list_length(func->args);
+ if (list_length(func->args) != 1)
+ elog(ERROR, "PREV/NEXT must have 1 argument but function %d has %d args", func->funcid, nargs);
+
+ expr = (Expr *) lfirst(list_head(func->args));
+ if (!IsA(expr, Var))
+ elog(ERROR, "PREV/NEXT's arg is not Var"); /* XXX: is it possible that arg type is Const? */
+ var = (Var *)expr;
+
+ if (func->funcid == F_PREV)
+ var->varno = OUTER_VAR;
+ else
+ var->varno = INNER_VAR;
+ }
+ return expression_tree_walker(node, attno_map_walker, (void *) context);
+ }
+ else if (IsA(node, Var))
+ {
+ var = (Var *)node;
+
+ elog(DEBUG1, "original varno: %d varattno: %d", var->varno, var->varattno);
+
+ forboth(lc1, attnomap->attno, lc2, attnomap->attnosyn)
+ {
+ int attno = lfirst_int(lc1);
+ int attnosyn = lfirst_int(lc2);
+
+ elog(DEBUG1, "walker: varattno: %d varattnosyn: %d",attno, attnosyn);
+ if (var->varattno == attnosyn)
+ {
+ elog(DEBUG1, "loc: %d rewrite varattno from: %d to %d", var->location, attnosyn, attno);
+ var->varattno = attno;
+ }
+ }
+ }
+ return expression_tree_walker(node, attno_map_walker, (void *) context);
+}
+
/* -----------------
* ExecEndWindowAgg
* -----------------
@@ -2691,6 +2919,8 @@ ExecEndWindowAgg(WindowAggState *node)
ExecClearTuple(node->agg_row_slot);
ExecClearTuple(node->temp_slot_1);
ExecClearTuple(node->temp_slot_2);
+ ExecClearTuple(node->prev_slot);
+ ExecClearTuple(node->next_slot);
if (node->framehead_slot)
ExecClearTuple(node->framehead_slot);
if (node->frametail_slot)
@@ -2740,6 +2970,8 @@ ExecReScanWindowAgg(WindowAggState *node)
ExecClearTuple(node->agg_row_slot);
ExecClearTuple(node->temp_slot_1);
ExecClearTuple(node->temp_slot_2);
+ ExecClearTuple(node->prev_slot);
+ ExecClearTuple(node->next_slot);
if (node->framehead_slot)
ExecClearTuple(node->framehead_slot);
if (node->frametail_slot)
@@ -3080,7 +3312,7 @@ are_peers(WindowAggState *winstate, TupleTableSlot *slot1,
*
* Returns true if successful, false if no such row
*/
-static bool
+bool
window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot)
{
WindowAggState *winstate = winobj->winstate;
@@ -3100,7 +3332,7 @@ window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot)
return false;
if (pos < winobj->markpos)
- elog(ERROR, "cannot fetch row before WindowObject's mark position");
+ elog(ERROR, "cannot fetch row: " INT64_FORMAT " before WindowObject's mark position: " INT64_FORMAT, pos, winobj->markpos );
oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
@@ -3420,14 +3652,54 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
WindowAggState *winstate;
ExprContext *econtext;
TupleTableSlot *slot;
- int64 abs_pos;
- int64 mark_pos;
Assert(WindowObjectIsValid(winobj));
winstate = winobj->winstate;
econtext = winstate->ss.ps.ps_ExprContext;
slot = winstate->temp_slot_1;
+ if (WinGetSlotInFrame(winobj, slot,
+ relpos, seektype, set_mark,
+ isnull, isout) == 0)
+ {
+ econtext->ecxt_outertuple = slot;
+ return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
+ econtext, isnull);
+ }
+
+ if (isout)
+ *isout = true;
+ *isnull = true;
+ return (Datum) 0;
+}
+
+/*
+ * WinGetSlotInFrame
+ * slot: TupleTableSlot to store the result
+ * relpos: signed rowcount offset from the seek position
+ * seektype: WINDOW_SEEK_HEAD or WINDOW_SEEK_TAIL
+ * set_mark: If the row is found/in frame and set_mark is true, the mark is
+ * moved to the row as a side-effect.
+ * isnull: output argument, receives isnull status of result
+ * isout: output argument, set to indicate whether target row position
+ * is out of frame (can pass NULL if caller doesn't care about this)
+ *
+ * Returns 0 if we successfullt got the slot. false if out of frame.
+ * (also isout is set)
+ */
+int
+WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot,
+ int relpos, int seektype, bool set_mark,
+ bool *isnull, bool *isout)
+{
+ WindowAggState *winstate;
+ int64 abs_pos;
+ int64 mark_pos;
+ int num_reduced_frame;
+
+ Assert(WindowObjectIsValid(winobj));
+ winstate = winobj->winstate;
+
switch (seektype)
{
case WINDOW_SEEK_CURRENT:
@@ -3494,6 +3766,12 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
winstate->frameOptions);
break;
}
+ num_reduced_frame = row_is_in_reduced_frame(winobj, winstate->frameheadpos);
+ if (num_reduced_frame < 0)
+ goto out_of_frame;
+ else if (num_reduced_frame > 0)
+ if (relpos >= num_reduced_frame)
+ goto out_of_frame;
break;
case WINDOW_SEEK_TAIL:
/* rejecting relpos > 0 is easy and simplifies code below */
@@ -3565,6 +3843,12 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
mark_pos = 0; /* keep compiler quiet */
break;
}
+
+ num_reduced_frame = row_is_in_reduced_frame(winobj, winstate->frameheadpos + relpos);
+ if (num_reduced_frame < 0)
+ goto out_of_frame;
+ else if (num_reduced_frame > 0)
+ abs_pos = winstate->frameheadpos + relpos + num_reduced_frame - 1;
break;
default:
elog(ERROR, "unrecognized window seek type: %d", seektype);
@@ -3583,15 +3867,13 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
*isout = false;
if (set_mark)
WinSetMarkPosition(winobj, mark_pos);
- econtext->ecxt_outertuple = slot;
- return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
- econtext, isnull);
+ return 0;
out_of_frame:
if (isout)
*isout = true;
*isnull = true;
- return (Datum) 0;
+ return -1;
}
/*
@@ -3622,3 +3904,400 @@ WinGetFuncArgCurrent(WindowObject winobj, int argno, bool *isnull)
return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
econtext, isnull);
}
+
+WindowAggState *
+WinGetAggState(WindowObject winobj)
+{
+ return winobj->winstate;
+}
+
+/*
+ * row_is_in_reduced_frame
+ * Determine whether a row is in the current row's reduced window frame according
+ * to row pattern matching
+ *
+ * The row must has been already determined that it is in a full window frame
+ * and fetched it into slot.
+ *
+ * Returns:
+ * = 0, RPR is not defined.
+ * >0, if the row is the first in the reduced frame. Return the number of rows in the reduced frame.
+ * -1, if the row is unmatched row
+ * -2, if the row is in the reduced frame but needed to be skipped because of
+ * AFTER MATCH SKIP PAST LAST ROW
+ */
+static
+int row_is_in_reduced_frame(WindowObject winobj, int64 pos)
+{
+ WindowAggState *winstate = winobj->winstate;
+ ListCell *lc1, *lc2;
+ bool expression_result;
+ int num_matched_rows;
+ int64 original_pos;
+ bool anymatch;
+ StringInfo encoded_str;
+ StringInfo pattern_str = makeStringInfo();
+
+ /*
+ * Array of pattern variables evaluted to true.
+ * Each character corresponds to pattern variable.
+ * Example:
+ * str_set[0] = "AB";
+ * str_set[1] = "AC";
+ * In this case at row 0 A and B are true, and A and C are true in row 1.
+ */
+ #define ENCODED_STR_ARRAY_ALLOC_SIZE 128
+ StringInfo *str_set = NULL;
+ int str_set_index;
+ int str_set_size;
+
+ if (winstate->patternVariableList == NIL)
+ {
+ /*
+ * RPR is not defined. Assume that we are always in the the reduced
+ * window frame.
+ */
+ return 0;
+ }
+
+ /* save original pos */
+ original_pos = pos;
+
+ /*
+ * Check whether the row speicied by pos is in the reduced frame. The
+ * second and subsequent rows need to be recognized as "unmatched" rows if
+ * AFTER MATCH SKIP PAST LAST ROW is defined.
+ */
+ if (winstate->rpSkipTo == ST_PAST_LAST_ROW &&
+ pos > winstate->headpos_in_reduced_frame &&
+ pos < (winstate->headpos_in_reduced_frame + winstate->num_rows_in_reduced_frame))
+ return -2;
+
+ /*
+ * Loop over until none of pattern matches or encounters end of frame.
+ */
+ for (;;)
+ {
+ int64 result_pos = -1;
+
+ /*
+ * Loop over each PATTERN variable.
+ */
+ anymatch = false;
+ encoded_str = makeStringInfo();
+
+ forboth(lc1, winstate->patternVariableList, lc2, winstate->patternRegexpList)
+ {
+ char *vname = strVal(lfirst(lc1));
+ char *quantifier = strVal(lfirst(lc2));
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " pattern vname: %s quantifier: %s", pos, vname, quantifier);
+
+ expression_result = false;
+
+ /* evaluate row pattern against current row */
+ result_pos = evaluate_pattern(winobj, pos, vname, encoded_str, &expression_result);
+ if (expression_result)
+ {
+ elog(DEBUG1, "expression result is true");
+ anymatch = true;
+ }
+
+ /*
+ * If out of frame, we are done.
+ */
+ if (result_pos < 0)
+ break;
+ }
+
+ if (!anymatch)
+ {
+ /* none of patterns matched. */
+ break;
+ }
+
+ /* build encoded string array */
+ if (str_set == NULL)
+ {
+ str_set_index = 0;
+ str_set_size = ENCODED_STR_ARRAY_ALLOC_SIZE * sizeof(StringInfo);
+ str_set = palloc(str_set_size);
+ }
+
+ str_set[str_set_index++] = encoded_str;
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " str_set_index: %d encoded_str: %s", pos, str_set_index, encoded_str->data);
+
+ if (str_set_index >= str_set_size)
+ {
+ str_set_size *= 2;
+ str_set = repalloc(str_set, str_set_size);
+ }
+
+ /* move to next row */
+ pos++;
+
+ if (result_pos < 0)
+ {
+ /* out of frame */
+ break;
+ }
+ }
+
+ if (str_set == NULL)
+ {
+ /* no matches found in the first row */
+ return -1;
+ }
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " encoded_str: %s", pos, encoded_str->data);
+
+ /* build regular expression */
+ pattern_str = makeStringInfo();
+ appendStringInfoChar(pattern_str, '^');
+ forboth(lc1, winstate->patternVariableList, lc2, winstate->patternRegexpList)
+ {
+ char *vname = strVal(lfirst(lc1));
+ char *quantifier = strVal(lfirst(lc2));
+
+ appendStringInfoChar(pattern_str, vname[0]);
+ if (quantifier[0])
+ appendStringInfoChar(pattern_str, quantifier[0]);
+ elog(DEBUG1, "vname: %s quantifier: %s", vname, quantifier);
+ }
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " pattern: %s", pos, pattern_str->data);
+
+ /* look for matching pattern variable sequence */
+ num_matched_rows = search_str_set(pattern_str->data, str_set, str_set_index);
+ if (num_matched_rows <= 0)
+ return -1;
+
+ /*
+ * We are at the first row in the reduced frame. Save the number of
+ * matched rows as the number of rows in the reduced frame.
+ */
+ winstate->headpos_in_reduced_frame = original_pos;
+ winstate->num_rows_in_reduced_frame = num_matched_rows;
+
+ return num_matched_rows;
+}
+
+/*
+ * search set of encode_str.
+ * set_size: size of set_str array.
+ */
+static
+int search_str_set(char *pattern, StringInfo *str_set, int set_size)
+{
+ char *encoded_str = palloc0(set_size+1);
+ int resultlen = 0;
+
+ search_str_set_recurse(pattern, str_set, set_size, 0, encoded_str, &resultlen);
+ elog(DEBUG1, "search_str_set returns %d", resultlen);
+ return resultlen;
+}
+
+static
+void search_str_set_recurse(char *pattern, StringInfo *str_set, int set_size, int set_index, char *encoded_str, int *resultlen)
+{
+ char *p;
+
+ if (set_index >= set_size)
+ {
+ Datum d;
+ text *res;
+ char *substr;
+
+ /*
+ * We first perform pattern matching using regexp_instr, then call
+ * textregexsubstr to get matched substring to know how log the
+ * matched string is. That is the number of rows in the reduced window
+ * frame. The reason why we can't call textregexsubstr is, it error
+ * out if pattern is not match.
+ */
+ if (DatumGetInt32(DirectFunctionCall2Coll(regexp_instr, DEFAULT_COLLATION_OID,
+ PointerGetDatum(cstring_to_text(encoded_str)),
+ PointerGetDatum(cstring_to_text(pattern)))) > 0)
+ {
+ d = DirectFunctionCall2Coll(textregexsubstr,
+ DEFAULT_COLLATION_OID,
+ PointerGetDatum(cstring_to_text(encoded_str)),
+ PointerGetDatum(cstring_to_text(pattern)));
+ if (d != 0)
+ {
+ int len;
+
+ res = DatumGetTextPP(d);
+ substr = text_to_cstring(res);
+ len = strlen(substr);
+ if (len > *resultlen)
+ /* remember the longest match */
+ *resultlen = len;
+ }
+ }
+ return;
+ }
+
+ p = str_set[set_index]->data;
+ while (*p)
+ {
+ encoded_str[set_index] = *p;
+ p++;
+ search_str_set_recurse(pattern, str_set, set_size, set_index + 1, encoded_str, resultlen);
+ }
+}
+
+
+/*
+ * Evaluate expression associated with PATTERN variable vname.
+ * relpos is relative row position in a frame (starting from 0).
+ * "quantifier" is the quatifier part of the PATTERN regular expression.
+ * Currently only '+' is allowed.
+ * result is out paramater representing the expression evaluation result
+ * is true of false.
+ * Return values are:
+ * >=0: the last match absolute row position
+ * other wise out of frame.
+ */
+static
+int64 evaluate_pattern(WindowObject winobj, int64 current_pos,
+ char *vname, StringInfo encoded_str, bool *result)
+{
+ WindowAggState *winstate = winobj->winstate;
+ ExprContext *econtext = winstate->ss.ps.ps_ExprContext;
+ ListCell *lc1, *lc2;
+ ExprState *pat;
+ Datum eval_result;
+ bool out_of_frame = false;
+ bool isnull;
+
+ forboth (lc1, winstate->defineVariableList, lc2, winstate->defineClauseList)
+ {
+ char *name = strVal(lfirst(lc1));
+
+ if (strcmp(vname, name))
+ continue;
+
+ /* set expression to evaluate */
+ pat = lfirst(lc2);
+
+ /* get current, previous and next tuples */
+ if (!get_slots(winobj, current_pos))
+ {
+ out_of_frame = true;
+ }
+ else
+ {
+ /* evaluate the expression */
+ eval_result = ExecEvalExpr(pat, econtext, &isnull);
+ if (isnull)
+ {
+ /* expression is NULL */
+ elog(DEBUG1, "expression for %s is NULL at row: " INT64_FORMAT, vname, current_pos);
+ *result = false;
+ }
+ else
+ {
+ if (!DatumGetBool(eval_result))
+ {
+ /* expression is false */
+ elog(DEBUG1, "expression for %s is false at row: " INT64_FORMAT, vname, current_pos);
+ *result = false;
+ }
+ else
+ {
+ /* expression is true */
+ elog(DEBUG1, "expression for %s is true at row: " INT64_FORMAT, vname, current_pos);
+ appendStringInfoChar(encoded_str, vname[0]);
+ *result = true;
+ }
+ }
+ break;
+ }
+
+ if (out_of_frame)
+ {
+ *result = false;
+ return -1;
+ }
+ }
+ return current_pos;
+}
+
+/*
+ * Get current, previous and next tuples.
+ * Returns false if current row is out of partition/full frame.
+ */
+static
+bool get_slots(WindowObject winobj, int64 current_pos)
+{
+ WindowAggState *winstate = winobj->winstate;
+ TupleTableSlot *slot;
+ int ret;
+ ExprContext *econtext;
+
+ econtext = winstate->ss.ps.ps_ExprContext;
+
+ /* set up current row tuple slot */
+ slot = winstate->temp_slot_1;
+ if (!window_gettupleslot(winobj, current_pos, slot))
+ {
+ elog(DEBUG1, "current row is out of partition at:" INT64_FORMAT, current_pos);
+ return false;
+
+ ret = row_is_in_frame(winstate, current_pos, slot);
+ if (ret <= 0)
+ {
+ elog(DEBUG1, "current row is out of frame at: " INT64_FORMAT, current_pos);
+ return false;
+ }
+ }
+ econtext->ecxt_scantuple = slot;
+
+ /* for PREV */
+ if (current_pos > 0)
+ {
+ slot = winstate->prev_slot;
+ if (!window_gettupleslot(winobj, current_pos - 1, slot))
+ {
+ elog(DEBUG1, "previous row is out of partition at: " INT64_FORMAT, current_pos - 1);
+ econtext->ecxt_outertuple = winstate->null_slot;
+ }
+ else
+ {
+ ret = row_is_in_frame(winstate, current_pos - 1, slot);
+ if (ret <= 0)
+ {
+ elog(DEBUG1, "previous row is out of frame at: " INT64_FORMAT, current_pos - 1);
+ econtext->ecxt_outertuple = winstate->null_slot;
+ }
+ else
+ {
+ econtext->ecxt_outertuple = slot;
+ }
+ }
+ }
+ else
+ econtext->ecxt_outertuple = winstate->null_slot;
+
+ /* for NEXT */
+ slot = winstate->next_slot;
+ if (!window_gettupleslot(winobj, current_pos + 1, slot))
+ {
+ elog(DEBUG1, "next row is out of partiton at: " INT64_FORMAT, current_pos + 1);
+ econtext->ecxt_innertuple = winstate->null_slot;
+ }
+ else
+ {
+ ret = row_is_in_frame(winstate, current_pos + 1, slot);
+ if (ret <= 0)
+ {
+ elog(DEBUG1, "next row is out of frame at: " INT64_FORMAT, current_pos + 1);
+ econtext->ecxt_innertuple = winstate->null_slot;
+ }
+ else
+ econtext->ecxt_innertuple = slot;
+ }
+ return true;
+}
diff --git a/src/backend/utils/adt/windowfuncs.c b/src/backend/utils/adt/windowfuncs.c
index b87a624fb2..e4cab36ec9 100644
--- a/src/backend/utils/adt/windowfuncs.c
+++ b/src/backend/utils/adt/windowfuncs.c
@@ -13,6 +13,9 @@
*/
#include "postgres.h"
+#include "catalog/pg_collation_d.h"
+#include "executor/executor.h"
+#include "nodes/execnodes.h"
#include "nodes/supportnodes.h"
#include "utils/builtins.h"
#include "windowapi.h"
@@ -36,11 +39,19 @@ typedef struct
int64 remainder; /* (total rows) % (bucket num) */
} ntile_context;
+/*
+ * rpr process information.
+ * Used for AFTER MATCH SKIP PAST LAST ROW
+ */
+typedef struct SkipContext
+{
+ int64 pos; /* last row absolute position */
+} SkipContext;
+
static bool rank_up(WindowObject winobj);
static Datum leadlag_common(FunctionCallInfo fcinfo,
bool forward, bool withoffset, bool withdefault);
-
/*
* utility routine for *_rank functions.
*/
@@ -673,7 +684,7 @@ window_last_value(PG_FUNCTION_ARGS)
bool isnull;
result = WinGetFuncArgInFrame(winobj, 0,
- 0, WINDOW_SEEK_TAIL, true,
+ 0, WINDOW_SEEK_TAIL, false,
&isnull, NULL);
if (isnull)
PG_RETURN_NULL();
@@ -713,3 +724,26 @@ window_nth_value(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(result);
}
+
+/*
+ * prev
+ * Dummy function to invoke RPR's navigation operator "PREV".
+ * This is *not* a window function.
+ */
+Datum
+window_prev(PG_FUNCTION_ARGS)
+{
+ PG_RETURN_DATUM(PG_GETARG_DATUM(0));
+}
+
+/*
+ * next
+ * Dummy function to invoke RPR's navigation operation "NEXT".
+ * This is *not* a window function.
+ */
+Datum
+window_next(PG_FUNCTION_ARGS)
+{
+ PG_RETURN_DATUM(PG_GETARG_DATUM(0));
+}
+
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6996073989..fa100b2665 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10397,6 +10397,12 @@
{ oid => '3114', descr => 'fetch the Nth row value',
proname => 'nth_value', prokind => 'w', prorettype => 'anyelement',
proargtypes => 'anyelement int4', prosrc => 'window_nth_value' },
+{ oid => '6122', descr => 'previous value',
+ proname => 'prev', provolatile => 's', prorettype => 'anyelement',
+ proargtypes => 'anyelement', prosrc => 'window_prev' },
+{ oid => '6123', descr => 'next value',
+ proname => 'next', provolatile => 's', prorettype => 'anyelement',
+ proargtypes => 'anyelement', prosrc => 'window_next' },
# functions for range types
{ oid => '3832', descr => 'I/O',
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index cb714f4a19..4fd3bd1a93 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -2519,6 +2519,14 @@ typedef struct WindowAggState
int64 groupheadpos; /* current row's peer group head position */
int64 grouptailpos; /* " " " " tail position (group end+1) */
+ /* these fields are used in Row pattern recognition: */
+ RPSkipTo rpSkipTo; /* Row Pattern Skip To type */
+ List *patternVariableList; /* list of row pattern variables names (list of String) */
+ List *patternRegexpList; /* list of row pattern regular expressions ('+' or ''. list of String) */
+ List *defineVariableList; /* list of row pattern definition variables (list of String) */
+ List *defineClauseList; /* expression for row pattern definition
+ * search conditions ExprState list */
+
MemoryContext partcontext; /* context for partition-lifespan data */
MemoryContext aggcontext; /* shared context for aggregate working data */
MemoryContext curaggcontext; /* current aggregate's working data */
@@ -2555,6 +2563,16 @@ typedef struct WindowAggState
TupleTableSlot *agg_row_slot;
TupleTableSlot *temp_slot_1;
TupleTableSlot *temp_slot_2;
+
+ /* temporary slots for RPR */
+ TupleTableSlot *prev_slot; /* PREV row navigation operator */
+ TupleTableSlot *next_slot; /* NEXT row navigation operator */
+ TupleTableSlot *null_slot; /* all NULL slot */
+
+ /* head of the reduced window frame */
+ int64 headpos_in_reduced_frame;
+ /* number of rows in the reduced window frame */
+ int64 num_rows_in_reduced_frame;
} WindowAggState;
/* ----------------
diff --git a/src/include/windowapi.h b/src/include/windowapi.h
index b8c2c565d1..1e292648e9 100644
--- a/src/include/windowapi.h
+++ b/src/include/windowapi.h
@@ -58,7 +58,15 @@ extern Datum WinGetFuncArgInFrame(WindowObject winobj, int argno,
int relpos, int seektype, bool set_mark,
bool *isnull, bool *isout);
+extern int WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot,
+ int relpos, int seektype, bool set_mark,
+ bool *isnull, bool *isout);
+
extern Datum WinGetFuncArgCurrent(WindowObject winobj, int argno,
bool *isnull);
+extern WindowAggState *WinGetAggState(WindowObject winobj);
+
+extern bool window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot);
+
#endif /* WINDOWAPI_H */
--
2.25.1
----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
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filename="v3-0005-Row-pattern-recognition-patch-docs.patch"
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