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[PATCH v6 4/7] Row pattern recognition patch (executor). 2+ messages / 2 participants [nested] [flat]
* [PATCH v6 4/7] Row pattern recognition patch (executor). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- src/backend/executor/nodeWindowAgg.c | 842 ++++++++++++++++++++++++++- src/backend/utils/adt/windowfuncs.c | 37 +- src/include/catalog/pg_proc.dat | 6 + src/include/nodes/execnodes.h | 26 + 4 files changed, 898 insertions(+), 13 deletions(-) diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c index 310ac23e3a..32270d051a 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 +198,32 @@ 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 bool rpr_is_defined(WindowAggState *winstate); + +static void create_reduced_frame_map(WindowAggState *winstate); +static int get_reduced_frame_map(WindowAggState *winstate, int64 pos); +static void register_reduced_frame_map(WindowAggState *winstate, int64 pos, int val); +static void clear_reduced_frame_map(WindowAggState *winstate); +static void update_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 +699,7 @@ eval_windowaggregates(WindowAggState *winstate) WindowObject agg_winobj; TupleTableSlot *agg_row_slot; TupleTableSlot *temp_slot; + bool agg_result_isnull; numaggs = winstate->numaggs; if (numaggs == 0) @@ -778,6 +805,9 @@ eval_windowaggregates(WindowAggState *winstate) * Note that we don't strictly need to restart in the last case, but if * we're going to remove all rows from the aggregation anyway, a restart * surely is faster. + * + * - if RPR is enabled and skip mode is SKIP TO NEXT ROW, + * we restart aggregation too. *---------- */ numaggs_restart = 0; @@ -788,8 +818,11 @@ eval_windowaggregates(WindowAggState *winstate) (winstate->aggregatedbase != winstate->frameheadpos && !OidIsValid(peraggstate->invtransfn_oid)) || (winstate->frameOptions & FRAMEOPTION_EXCLUSION) || - winstate->aggregatedupto <= winstate->frameheadpos) + winstate->aggregatedupto <= winstate->frameheadpos || + (rpr_is_defined(winstate) && + winstate->rpSkipTo == ST_NEXT_ROW)) { + elog(DEBUG1, "peraggstate->restart is set"); peraggstate->restart = true; numaggs_restart++; } @@ -861,8 +894,10 @@ 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. @@ -917,6 +952,29 @@ eval_windowaggregates(WindowAggState *winstate) { winstate->aggregatedupto = winstate->frameheadpos; ExecClearTuple(agg_row_slot); + + /* + * If RPR is defined, we do not use aggregatedupto_nonrestarted. To + * avoid assertion failure below, we reset aggregatedupto_nonrestarted + * to frameheadpos. + */ + if (rpr_is_defined(winstate)) + aggregatedupto_nonrestarted = winstate->frameheadpos; + } + + agg_result_isnull = false; + /* RPR is defined? */ + if (rpr_is_defined(winstate)) + { + /* + * If the skip mode is SKIP TO PAST LAST ROW and we already know that + * current row is a skipped row or an unmatched row, we don't need to + * accumulate rows, just return NULL. + */ + if (winstate->rpSkipTo == ST_PAST_LAST_ROW && + (get_reduced_frame_map(winstate, winstate->currentpos) == RF_SKIPPED || + get_reduced_frame_map(winstate, winstate->currentpos) == RF_UNMATCHED)) + agg_result_isnull = true; } /* @@ -930,6 +988,11 @@ eval_windowaggregates(WindowAggState *winstate) { int ret; + elog(DEBUG1, "===== loop in frame starts: " INT64_FORMAT, winstate->aggregatedupto); + + if (agg_result_isnull) + break; + /* Fetch next row if we didn't already */ if (TupIsNull(agg_row_slot)) { @@ -945,9 +1008,28 @@ eval_windowaggregates(WindowAggState *winstate) ret = row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot); if (ret < 0) break; + if (ret == 0) goto next_tuple; + if (rpr_is_defined(winstate)) + { + /* + * If the row status at currentpos is already decided and current + * row status is not decided yet, it means we passed the last + * reduced frame. Time to break the loop. + */ + if (get_reduced_frame_map(winstate, winstate->currentpos) != RF_NOT_DETERMINED && + get_reduced_frame_map(winstate, winstate->aggregatedupto) == RF_NOT_DETERMINED) + break; + /* + * Otherwise we need to calculate the reduced frame. + */ + ret = row_is_in_reduced_frame(winstate->agg_winobj, winstate->aggregatedupto); + if (ret == -1) /* unmatched row */ + break; + } + /* Set tuple context for evaluation of aggregate arguments */ winstate->tmpcontext->ecxt_outertuple = agg_row_slot; @@ -976,6 +1058,7 @@ next_tuple: ExecClearTuple(agg_row_slot); } + /* The frame's end is not supposed to move backwards, ever */ Assert(aggregatedupto_nonrestarted <= winstate->aggregatedupto); @@ -996,6 +1079,16 @@ next_tuple: peraggstate, result, isnull); + /* + * RPR is enabled and we just return NULL. because skip mode is SKIP + * TO PAST LAST ROW and current row is skipped row or unmatched row. + */ + if (agg_result_isnull) + { + *isnull = true; + *result = (Datum) 0; + } + /* * save the result in case next row shares the same frame. * @@ -1090,6 +1183,7 @@ begin_partition(WindowAggState *winstate) winstate->framehead_valid = false; winstate->frametail_valid = false; winstate->grouptail_valid = false; + create_reduced_frame_map(winstate); winstate->spooled_rows = 0; winstate->currentpos = 0; winstate->frameheadpos = 0; @@ -2053,6 +2147,8 @@ ExecWindowAgg(PlanState *pstate) CHECK_FOR_INTERRUPTS(); + elog(DEBUG1, "ExecWindowAgg called. pos: " INT64_FORMAT , winstate->currentpos); + if (winstate->status == WINDOWAGG_DONE) return NULL; @@ -2221,6 +2317,17 @@ ExecWindowAgg(PlanState *pstate) /* don't evaluate the window functions when we're in pass-through mode */ if (winstate->status == WINDOWAGG_RUN) { + /* + * If RPR is defined and skip mode is next row, we need to clear existing + * reduced frame info so that we newly calculate the info starting from + * current row. + */ + if (rpr_is_defined(winstate)) + { + if (winstate->rpSkipTo == ST_NEXT_ROW) + clear_reduced_frame_map(winstate); + } + /* * Evaluate true window functions */ @@ -2388,6 +2495,9 @@ 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 +2593,16 @@ 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 +2787,39 @@ 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 +2827,57 @@ 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 +2895,8 @@ 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 +2946,8 @@ 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 +3308,7 @@ 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 +3628,54 @@ 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: @@ -3494,11 +3742,21 @@ 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 */ if (relpos > 0) goto out_of_frame; + + /* RPR cares about frame head pos. Need to call update_frameheadpos */ + update_frameheadpos(winstate); + update_frametailpos(winstate); abs_pos = winstate->frametailpos - 1 + relpos; @@ -3565,6 +3823,12 @@ 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 +3847,13 @@ 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 +3884,561 @@ WinGetFuncArgCurrent(WindowObject winobj, int argno, bool *isnull) return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno), econtext, isnull); } + +/* + * rpr_is_defined + * return true if Row pattern recognition is defined. + */ +static +bool rpr_is_defined(WindowAggState *winstate) +{ + return winstate->patternVariableList != NIL; +} + +/* + * 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; + int state; + int rtn; + + if (!rpr_is_defined(winstate)) + { + /* + * RPR is not defined. Assume that we are always in the the reduced + * window frame. + */ + rtn = 0; + elog(DEBUG1, "row_is_in_reduced_frame returns %d: pos: " INT64_FORMAT, rtn, pos); + return rtn; + } + + state = get_reduced_frame_map(winstate, pos); + + if (state == RF_NOT_DETERMINED) + { + update_frameheadpos(winstate); + update_reduced_frame(winobj, pos); + } + + state = get_reduced_frame_map(winstate, pos); + + switch (state) + { + int64 i; + int num_reduced_rows; + + case RF_FRAME_HEAD: + num_reduced_rows = 1; + for (i = pos + 1; get_reduced_frame_map(winstate,i) == RF_SKIPPED; i++) + num_reduced_rows++; + rtn = num_reduced_rows; + break; + + case RF_SKIPPED: + rtn = -2; + break; + + case RF_UNMATCHED: + rtn = -1; + break; + + default: + elog(ERROR, "Unrecognized state: %d at: " INT64_FORMAT, state, pos); + break; + } + + elog(DEBUG1, "row_is_in_reduced_frame returns %d: pos: " INT64_FORMAT, rtn, pos); + return rtn; +} + +#define REDUCED_FRAME_MAP_INIT_SIZE 1024L + +/* + * Create reduced frame map + */ +static +void create_reduced_frame_map(WindowAggState *winstate) +{ + winstate->reduced_frame_map = + MemoryContextAlloc(winstate->partcontext, REDUCED_FRAME_MAP_INIT_SIZE); + winstate->alloc_sz = REDUCED_FRAME_MAP_INIT_SIZE; + clear_reduced_frame_map(winstate); +} + +/* + * Clear reduced frame map + */ +static +void clear_reduced_frame_map(WindowAggState *winstate) +{ + Assert(winstate->reduced_frame_map != NULL); + MemSet(winstate->reduced_frame_map, RF_NOT_DETERMINED, + winstate->alloc_sz); +} + +/* + * Get reduced frame map specified by pos + */ +static +int get_reduced_frame_map(WindowAggState *winstate, int64 pos) +{ + Assert(winstate->reduced_frame_map != NULL); + + if (pos < 0 || pos >= winstate->alloc_sz) + elog(ERROR, "wrong pos: " INT64_FORMAT, pos); + + return winstate->reduced_frame_map[pos]; +} + +/* + * Add/replace reduced frame map member at pos. + * If there's no enough space, expand the map. + */ +static +void register_reduced_frame_map(WindowAggState *winstate, int64 pos, int val) +{ + int64 realloc_sz; + + Assert(winstate->reduced_frame_map != NULL); + + if (pos < 0) + elog(ERROR, "wrong pos: " INT64_FORMAT, pos); + + if (pos > winstate->alloc_sz - 1) + { + realloc_sz = winstate->alloc_sz * 2; + + winstate->reduced_frame_map = + repalloc(winstate->reduced_frame_map, realloc_sz); + + MemSet(winstate->reduced_frame_map + winstate->alloc_sz, + RF_NOT_DETERMINED, realloc_sz - winstate->alloc_sz); + + winstate->alloc_sz = realloc_sz; + } + + winstate->reduced_frame_map[pos] = val; +} + +/* + * update_reduced_frame + * Update reduced frame info. + */ +static +void update_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; + + /* save original pos */ + original_pos = pos; + + /* + * 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 match found in the first row */ + register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED); + return; + } + + elog(DEBUG2, "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(DEBUG2, "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); + /* + * 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. + */ + if (num_matched_rows <= 0) + { + /* no match */ + register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED); + } + else + { + int64 i; + + register_reduced_frame_map(winstate, original_pos, RF_FRAME_HEAD); + + for (i = original_pos + 1; i < original_pos + num_matched_rows; i++) + { + register_reduced_frame_map(winstate, i, RF_SKIPPED); + } + } + + return; +} + +/* + * 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; +} + +/* + * Workhorse of search_str_set. + */ +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)); + + 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..9ebcc7b5d2 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 +724,25 @@ 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..63feb68f60 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -2471,6 +2471,11 @@ typedef enum WindowAggStatus * tuples during spool */ } WindowAggStatus; +#define RF_NOT_DETERMINED 0 +#define RF_FRAME_HEAD 1 +#define RF_SKIPPED 2 +#define RF_UNMATCHED 3 + typedef struct WindowAggState { ScanState ss; /* its first field is NodeTag */ @@ -2519,6 +2524,15 @@ 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 +2569,18 @@ 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 */ + + /* + * Each byte corresponds to a row positioned at absolute its pos in + * partition. See above definition for RF_* + */ + char *reduced_frame_map; + int64 alloc_sz; /* size of the map */ } WindowAggState; /* ---------------- -- 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="v6-0005-Row-pattern-recognition-patch-docs.patch" ^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: A modest proposal: make parser/rewriter/planner inputs read-only @ 2025-04-15 17:31 Tom Lane <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Tom Lane @ 2025-04-15 17:31 UTC (permalink / raw) To: Richard Guo <[email protected]>; +Cc: [email protected] Richard Guo <[email protected]> writes: > On Sun, Apr 6, 2025 at 1:46 AM Tom Lane <[email protected]> wrote: >> Years ago we fixed the executor to treat its input Plan trees as >> read-only. It seems like we really ought to do the same for these >> upstream subsystems. Surely, whatever benefit we get from changing >> Node contents in-place is lost due to all these other hacks. > While I'm in favor of this idea, it seems that it will require lots of > code changes. In particular, within the planner, the parsetree goes > through considerable transformations during the preprocessing phase, > such as subquery pull-up, constant folding, and so on. Would this > proposal mean we'd need to refactor all those places to treat the > input parsetrees as read-only? Just trying to understand the scope of > what would be involved. From a high-level point of view, I'd be satisfied to have this property at the subsystem level: parse analysis can't modify the raw parse tree output by the grammar, rewriter can't modify the analyzed parse tree it's given, planner can't modify the parse tree it's given. That would not preclude, say, portions of the planner doing modify-in-place as long as it was certain that what they were modifying was a planner-local copy. (The proposed test infrastructure would only be able to enforce things at the subsystem level anyway.) As we get into the project we might decide that it'd be worth enforcing similar rules on portions of those subsystems, eg successive phases of the planner. I don't have strong feelings about that at present. An example here is that it'd be nice to have some way of verifying that a GEQO search step doesn't change any of the data structures that are supposed to remain the same. I do suspect that there are specific functions that will need to be made strict about this, for example eval_const_expressions, but that doesn't necessarily translate to a hard requirement across the board. regards, tom lane ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2025-04-15 17:31 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2023-09-12 05:22 [PATCH v6 4/7] Row pattern recognition patch (executor). Tatsuo Ishii <[email protected]> 2025-04-15 17:31 Re: A modest proposal: make parser/rewriter/planner inputs read-only Tom Lane <[email protected]>
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