From 1c08e3ea0c567ddd0a85e215b530d67bbcd6e836 Mon Sep 17 00:00:00 2001 From: Tatsuo Ishii Date: Mon, 17 Nov 2025 15:51:14 +0900 Subject: [PATCH v34 2/8] Row pattern recognition patch (parse/analysis). --- src/backend/parser/parse_agg.c | 7 + src/backend/parser/parse_clause.c | 270 +++++++++++++++++++++++++++++- src/backend/parser/parse_expr.c | 6 + src/backend/parser/parse_func.c | 3 + 4 files changed, 285 insertions(+), 1 deletion(-) diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index 3254c83cc6c..e820adf9267 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -580,6 +580,10 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr) errkind = true; break; + case EXPR_KIND_RPR_DEFINE: + errkind = true; + break; + /* * There is intentionally no default: case here, so that the * compiler will warn if we add a new ParseExprKind without @@ -996,6 +1000,9 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, case EXPR_KIND_CYCLE_MARK: errkind = true; break; + case EXPR_KIND_RPR_DEFINE: + errkind = true; + break; /* * There is intentionally no default: case here, so that the diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index ca26f6f61f2..3521d2780e2 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -96,7 +96,12 @@ static WindowClause *findWindowClause(List *wclist, const char *name); static Node *transformFrameOffset(ParseState *pstate, int frameOptions, Oid rangeopfamily, Oid rangeopcintype, Oid *inRangeFunc, Node *clause); - +static void transformRPR(ParseState *pstate, WindowClause *wc, WindowDef *windef, + List **targetlist); +static List *transformDefineClause(ParseState *pstate, WindowClause *wc, WindowDef *windef, + List **targetlist); +static void transformPatternClause(ParseState *pstate, WindowClause *wc, + WindowDef *windef); /* * transformFromClause - @@ -3019,6 +3024,10 @@ transformWindowDefinitions(ParseState *pstate, rangeopfamily, rangeopcintype, &wc->endInRangeFunc, windef->endOffset); + + /* Process Row Pattern Recognition related clauses */ + transformRPR(pstate, wc, windef, targetlist); + wc->winref = winref; result = lappend(result, wc); @@ -3886,3 +3895,262 @@ transformFrameOffset(ParseState *pstate, int frameOptions, return node; } + +/* + * transformRPR + * Process Row Pattern Recognition related clauses + */ +static void +transformRPR(ParseState *pstate, WindowClause *wc, WindowDef *windef, + List **targetlist) +{ + /* + * Window definition exists? + */ + if (windef == NULL) + return; + + /* + * Row Pattern Common Syntax clause exists? + */ + if (windef->rpCommonSyntax == NULL) + return; + + /* Check Frame option. Frame must start at current row */ + if ((wc->frameOptions & FRAMEOPTION_START_CURRENT_ROW) == 0) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("FRAME must start at current row when row patttern recognition is used"))); + + /* Transform AFTER MACH SKIP TO clause */ + wc->rpSkipTo = windef->rpCommonSyntax->rpSkipTo; + + /* Transform SEEK or INITIAL clause */ + wc->initial = windef->rpCommonSyntax->initial; + + /* Transform DEFINE clause into list of TargetEntry's */ + wc->defineClause = transformDefineClause(pstate, wc, windef, targetlist); + + /* Check PATTERN clause and copy to patternClause */ + transformPatternClause(pstate, wc, windef); +} + +/* + * transformDefineClause + * Process DEFINE clause and transform ResTarget into list of + * TargetEntry. + * + * XXX we only support column reference in row pattern definition search + * condition, e.g. "price". . is not supported, e.g. "A.price". + */ +static List * +transformDefineClause(ParseState *pstate, WindowClause *wc, WindowDef *windef, + List **targetlist) +{ + /* DEFINE variable name initials */ + static char *defineVariableInitials = "abcdefghijklmnopqrstuvwxyz"; + + ListCell *lc, + *l; + ResTarget *restarget, + *r; + List *restargets; + List *defineClause; + char *name; + int initialLen; + int i; + + /* + * If Row Definition Common Syntax exists, DEFINE clause must exist. (the + * raw parser should have already checked it.) + */ + Assert(windef->rpCommonSyntax->rpDefs != NULL); + + /* + * Check and add "A AS A IS TRUE" if pattern variable is missing in DEFINE + * per the SQL standard. + */ + restargets = NIL; + foreach(lc, windef->rpCommonSyntax->rpPatterns) + { + A_Expr *a; + bool found = false; + + if (!IsA(lfirst(lc), A_Expr)) + ereport(ERROR, + errmsg("node type is not A_Expr")); + + a = (A_Expr *) lfirst(lc); + name = strVal(a->lexpr); + + foreach(l, windef->rpCommonSyntax->rpDefs) + { + restarget = (ResTarget *) lfirst(l); + + if (!strcmp(restarget->name, name)) + { + found = true; + break; + } + } + + if (!found) + { + /* + * "name" is missing. So create "name AS name IS TRUE" ResTarget + * node and add it to the temporary list. + */ + A_Const *n; + + restarget = makeNode(ResTarget); + n = makeNode(A_Const); + n->val.boolval.type = T_Boolean; + n->val.boolval.boolval = true; + n->location = -1; + restarget->name = pstrdup(name); + restarget->indirection = NIL; + restarget->val = (Node *) n; + restarget->location = -1; + restargets = lappend((List *) restargets, restarget); + } + } + + if (list_length(restargets) >= 1) + { + /* add missing DEFINEs */ + windef->rpCommonSyntax->rpDefs = + list_concat(windef->rpCommonSyntax->rpDefs, restargets); + list_free(restargets); + } + + /* + * Check for duplicate row pattern definition variables. The standard + * requires that no two row pattern definition variable names shall be + * equivalent. + */ + restargets = NIL; + foreach(lc, windef->rpCommonSyntax->rpDefs) + { + restarget = (ResTarget *) lfirst(lc); + name = restarget->name; + + /* + * Add DEFINE expression (Restarget->val) to the targetlist as a + * TargetEntry if it does not exist yet. Planner will add the column + * ref var node to the outer plan's target list later on. This makes + * DEFINE expression could access the outer tuple while evaluating + * PATTERN. + * + * XXX: adding whole expressions of DEFINE to the plan.targetlist is + * not so good, because it's not necessary to evalute the expression + * in the target list while running the plan. We should extract the + * var nodes only then add them to the plan.targetlist. + */ + findTargetlistEntrySQL99(pstate, (Node *) restarget->val, + targetlist, EXPR_KIND_RPR_DEFINE); + + /* + * Make sure that the row pattern definition search condition is a + * boolean expression. + */ + transformWhereClause(pstate, restarget->val, + EXPR_KIND_RPR_DEFINE, "DEFINE"); + + foreach(l, restargets) + { + char *n; + + r = (ResTarget *) lfirst(l); + n = r->name; + + if (!strcmp(n, name)) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("row pattern definition variable name \"%s\" appears more than once in DEFINE clause", + name), + parser_errposition(pstate, exprLocation((Node *) r)))); + } + restargets = lappend(restargets, restarget); + } + list_free(restargets); + + /* + * Create list of row pattern DEFINE variable name's initial. We assign + * [a-z] to them (up to 26 variable names are allowed). + */ + restargets = NIL; + i = 0; + initialLen = strlen(defineVariableInitials); + + foreach(lc, windef->rpCommonSyntax->rpDefs) + { + char initial[2]; + + restarget = (ResTarget *) lfirst(lc); + name = restarget->name; + + if (i >= initialLen) + { + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("number of row pattern definition variable names exceeds %d", + initialLen), + parser_errposition(pstate, + exprLocation((Node *) restarget)))); + } + initial[0] = defineVariableInitials[i++]; + initial[1] = '\0'; + wc->defineInitial = lappend(wc->defineInitial, + makeString(pstrdup(initial))); + } + + defineClause = transformTargetList(pstate, windef->rpCommonSyntax->rpDefs, + EXPR_KIND_RPR_DEFINE); + + /* mark column origins */ + markTargetListOrigins(pstate, defineClause); + + /* mark all nodes in the DEFINE clause tree with collation information */ + assign_expr_collations(pstate, (Node *) defineClause); + + return defineClause; +} + +/* + * transformPatternClause + * Process PATTERN clause and return PATTERN clause in the raw parse tree + */ +static void +transformPatternClause(ParseState *pstate, WindowClause *wc, + WindowDef *windef) +{ + ListCell *lc; + + /* + * Row Pattern Common Syntax clause exists? + */ + if (windef->rpCommonSyntax == NULL) + return; + + wc->patternVariable = NIL; + wc->patternRegexp = NIL; + foreach(lc, windef->rpCommonSyntax->rpPatterns) + { + A_Expr *a; + char *name; + char *regexp; + + if (!IsA(lfirst(lc), A_Expr)) + ereport(ERROR, + errmsg("node type is not A_Expr")); + + a = (A_Expr *) lfirst(lc); + name = strVal(a->lexpr); + + wc->patternVariable = lappend(wc->patternVariable, makeString(pstrdup(name))); + regexp = strVal(lfirst(list_head(a->name))); + + wc->patternRegexp = lappend(wc->patternRegexp, makeString(pstrdup(regexp))); + } +} diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 32d6ae918ca..2c6af185bdb 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -576,6 +576,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) case EXPR_KIND_COPY_WHERE: case EXPR_KIND_GENERATED_COLUMN: case EXPR_KIND_CYCLE_MARK: + case EXPR_KIND_RPR_DEFINE: /* okay */ break; @@ -1861,6 +1862,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink) case EXPR_KIND_GENERATED_COLUMN: err = _("cannot use subquery in column generation expression"); break; + case EXPR_KIND_RPR_DEFINE: + err = _("cannot use subquery in DEFINE expression"); + break; /* * There is intentionally no default: case here, so that the @@ -3220,6 +3224,8 @@ ParseExprKindName(ParseExprKind exprKind) return "GENERATED AS"; case EXPR_KIND_CYCLE_MARK: return "CYCLE"; + case EXPR_KIND_RPR_DEFINE: + return "DEFINE"; /* * There is intentionally no default: case here, so that the diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c index 778d69c6f3c..13c6500a087 100644 --- a/src/backend/parser/parse_func.c +++ b/src/backend/parser/parse_func.c @@ -2783,6 +2783,9 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location) case EXPR_KIND_CYCLE_MARK: errkind = true; break; + case EXPR_KIND_RPR_DEFINE: + errkind = true; + break; /* * There is intentionally no default: case here, so that the -- 2.43.0