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* [PATCH v5 4/7] Row pattern recognition patch (executor).
@ 2023-09-02 06:32 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw)
---
src/backend/executor/nodeWindowAgg.c | 671 ++++++++++++++++++++++++++-
src/backend/utils/adt/windowfuncs.c | 38 +-
src/include/catalog/pg_proc.dat | 6 +
src/include/nodes/execnodes.h | 19 +
4 files changed, 722 insertions(+), 12 deletions(-)
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 310ac23e3a..2e59369a71 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"
@@ -182,8 +184,9 @@ 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 +198,25 @@ 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 int WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot,
+ int relpos, int seektype, bool set_mark,
+ bool *isnull, bool *isout);
+static bool window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot);
+
+static void attno_map(Node *node);
+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);
+static char pattern_initial(WindowAggState *winstate, char *vname);
/*
* initialize_windowaggregate
@@ -673,6 +692,9 @@ 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 +812,7 @@ 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 +884,10 @@ 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 +944,10 @@ 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 +959,18 @@ 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 +979,47 @@ 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 +1048,8 @@ 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 +2127,8 @@ ExecWindowAgg(PlanState *pstate)
CHECK_FOR_INTERRUPTS();
+ elog(DEBUG1, "ExecWindowAgg called. pos: " INT64_FORMAT , winstate->currentpos);
+
if (winstate->status == WINDOWAGG_DONE)
return NULL;
@@ -2388,6 +2464,9 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
TupleDesc scanDesc;
ListCell *l;
+ TargetEntry *te;
+ Expr *expr;
+
/* check for unsupported flags */
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
@@ -2483,6 +2562,16 @@ 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 +2756,39 @@ 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 */
+ winstate->defineInitial = node->defineInitial;
+ winstate->defineVariableList = NIL;
+ winstate->defineClauseList = NIL;
+ if (node->defineClause != NIL)
+ {
+ /*
+ * Tweak arg var of PREV/NEXT so that it refers to scan/inner slot.
+ */
+ 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)));
+ attno_map((Node *)expr);
+ 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 +2796,57 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
return winstate;
}
+/*
+ * Rewrite varno of Var node that is the argument of PREV/NET so that it sees
+ * scan tuple (PREV) or inner tuple (NEXT).
+ */
+static void
+attno_map(Node *node)
+{
+ (void) expression_tree_walker(node, attno_map_walker, NULL);
+}
+
+static bool
+attno_map_walker(Node *node, void *context)
+{
+ FuncExpr *func;
+ int nargs;
+ Expr *expr;
+ Var *var;
+
+ if (node == NULL)
+ return false;
+
+ 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)
+ /*
+ * Rewrite varno from OUTER_VAR to regular var no so that the
+ * var references scan tuple.
+ */
+ var->varno = var->varnosyn;
+ else
+ var->varno = INNER_VAR;
+ elog(DEBUG1, "PREV/NEXT's varno is rewritten to: %d", var->varno);
+ }
+ }
+ return expression_tree_walker(node, attno_map_walker, NULL);
+}
+
/* -----------------
* ExecEndWindowAgg
* -----------------
@@ -2691,6 +2864,8 @@ 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 +2915,8 @@ 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)
@@ -3100,7 +3277,7 @@ 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 +3597,54 @@ 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)
+ */
+static 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 +3711,12 @@ 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 +3788,12 @@ 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 +3812,13 @@ 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 +3849,427 @@ WinGetFuncArgCurrent(WindowObject winobj, int argno, bool *isnull)
return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
econtext, isnull);
}
+
+/*
+ * 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));
+ char initial;
+
+ initial = pattern_initial(winstate, vname);
+ Assert(initial != 0);
+ appendStringInfoChar(pattern_str, initial);
+ if (quantifier[0])
+ appendStringInfoChar(pattern_str, quantifier[0]);
+ elog(DEBUG1, "vname: %s initial: %c quantifier: %s", vname, initial, 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, *lc3;
+ ExprState *pat;
+ Datum eval_result;
+ bool out_of_frame = false;
+ bool isnull;
+
+ forthree (lc1, winstate->defineVariableList, lc2, winstate->defineClauseList, lc3, winstate->defineInitial)
+ {
+ char initial;
+ char *name = strVal(lfirst(lc1));
+
+ elog(DEBUG1, "evaluate_pattern: define variable: %s, pattern variable: %s", name, vname);
+
+ if (strcmp(vname, name))
+ continue;
+
+ initial = *(strVal(lfirst(lc3)));
+
+ /* 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, initial);
+ *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_outertuple = 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_scantuple = 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_scantuple = winstate->null_slot;
+ }
+ else
+ {
+ econtext->ecxt_scantuple = slot;
+ }
+ }
+ }
+ else
+ econtext->ecxt_scantuple = 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;
+}
+
+/*
+ * Return pattern variable initial character
+ * matching with pattern variable name vname.
+ * If not found, return 0.
+ */
+static
+char pattern_initial(WindowAggState *winstate, char *vname)
+{
+ char initial;
+ char *name;
+ ListCell *lc1, *lc2;
+
+ forboth (lc1, winstate->defineVariableList, lc2, winstate->defineInitial)
+ {
+ name = strVal(lfirst(lc1)); /* DEFINE variable name */
+ initial = *(strVal(lfirst(lc2))); /* DEFINE variable initial */
+
+
+ if (!strcmp(name, vname))
+ return initial; /* found */
+ }
+ return 0;
+}
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 9805bc6118..d20f803cf5 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10416,6 +10416,12 @@
{ 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..2bd6fcb5e1 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -2519,6 +2519,15 @@ 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 */
+ List *defineInitial; /* list of row pattern definition variable initials (list of String) */
+
MemoryContext partcontext; /* context for partition-lifespan data */
MemoryContext aggcontext; /* shared context for aggregate working data */
MemoryContext curaggcontext; /* current aggregate's working data */
@@ -2555,6 +2564,16 @@ 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;
/* ----------------
--
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="v5-0005-Row-pattern-recognition-patch-docs.patch"
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Buffer Cache Problem
@ 2023-11-10 14:38 jacktby jacktby <[email protected]>
2023-11-10 16:46 ` Re: Buffer Cache Problem jacktby jacktby <[email protected]>
0 siblings, 1 reply; 3+ messages in thread
From: jacktby jacktby @ 2023-11-10 14:38 UTC (permalink / raw)
To: [email protected]
> 2023年11月10日 22:31，jacktby jacktby <[email protected]> 写道：
>
> In the bus_internal.h,I see
> ====================================================
> Note: Buffer header lock (BM_LOCKED flag) must be held to examine or change tag, state or wait_backend_pgprocno fields.
> ====================================================
> As we all know, this buffer header lock is implemented by a bit in state filed, and this state field is a atomic_u32 type, so in fact we don’t need to
> hold buffer lock when we update state, this comment has error，right?
Oh, sorry this is true, in fact we never acquire a spin lock when update the state.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Buffer Cache Problem
2023-11-10 14:38 Re: Buffer Cache Problem jacktby jacktby <[email protected]>
@ 2023-11-10 16:46 ` jacktby jacktby <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: jacktby jacktby @ 2023-11-10 16:46 UTC (permalink / raw)
To: [email protected]; +Cc: [email protected]
Hi, I have 3 questions here:
1. I see comments in but_internals.h below:
========================================
* Also, in places we do one-time reads of the flags without bothering to
* lock the buffer header; this is generally for situations where we don't
* expect the flag bit being tested to be changing.
========================================
In fact, the flag is in state filed which is an atomic_u32, so we don’t need to acquire buffer header lock in any case, but for this comment, seems it’s saying we need to hold a buffer header lock when read flag in general.
2. Another question:
========================================
* We can't physically remove items from a disk page if another backend has
* the buffer pinned. Hence, a backend may need to wait for all other pins
* to go away. This is signaled by storing its own pgprocno into
* wait_backend_pgprocno and setting flag bit BM_PIN_COUNT_WAITER. At present,
* there can be only one such waiter per buffer.
========================================
The comments above, in fact for now, if a backend plan to remove items from a disk page, this is a mutation operation, so this backend must hold a exclusive lock for this buffer page, then in this case, there are no other backends pinning this buffer, so the pin refcount must be 1 (it’s by this backend), then this backend can remove the items safely and no need to wait other backends (because there are no other backends pinning this buffer). So my question is below:
The operation “storing its own pgprocno into
* wait_backend_pgprocno and setting flag bit BM_PIN_COUNT_WAITER” is whether too expensive, we should not do like this, right?
3. Where is the array?
========================================
* Per-buffer I/O condition variables are currently kept outside this struct in
* a separate array. They could be moved in here and still fit within that
* limit on common systems, but for now that is not done.
========================================
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2023-11-10 16:46 UTC | newest]
Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2023-09-02 06:32 [PATCH v5 4/7] Row pattern recognition patch (executor). Tatsuo Ishii <[email protected]>
2023-11-10 14:38 Re: Buffer Cache Problem jacktby jacktby <[email protected]>
2023-11-10 16:46 ` Re: Buffer Cache Problem jacktby jacktby <[email protected]>
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