diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 125 |
1 files changed, 30 insertions, 95 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 7bc70bd22c4..322aeba1ce3 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.44 1999/08/09 00:51:24 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.45 1999/08/10 03:00:15 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -78,7 +78,8 @@ bool is_opclause(Node *clause) { return (clause != NULL && - nodeTag(clause) == T_Expr && ((Expr *) clause)->opType == OP_EXPR); + IsA(clause, Expr) && + ((Expr *) clause)->opType == OP_EXPR); } /* @@ -147,7 +148,7 @@ bool is_funcclause(Node *clause) { return (clause != NULL && - nodeTag(clause) == T_Expr && + IsA(clause, Expr) && ((Expr *) clause)->opType == FUNC_EXPR); } @@ -183,9 +184,9 @@ make_funcclause(Func *func, List *funcargs) bool or_clause(Node *clause) { - return clause != NULL && - nodeTag(clause) == T_Expr && - ((Expr *) clause)->opType == OR_EXPR; + return (clause != NULL && + IsA(clause, Expr) && + ((Expr *) clause)->opType == OR_EXPR); } /* @@ -220,7 +221,7 @@ bool not_clause(Node *clause) { return (clause != NULL && - nodeTag(clause) == T_Expr && + IsA(clause, Expr) && ((Expr *) clause)->opType == NOT_EXPR); } @@ -269,7 +270,7 @@ bool and_clause(Node *clause) { return (clause != NULL && - nodeTag(clause) == T_Expr && + IsA(clause, Expr) && ((Expr *) clause)->opType == AND_EXPR); } @@ -319,27 +320,10 @@ make_ands_implicit(Expr *clause) return lcons(clause, NIL); } -/***************************************************************************** - * CASE clause functions - *****************************************************************************/ - - -/* - * case_clause - * - * Returns t iff its argument is a 'case' clause: (CASE { expr }). - * - */ -bool -case_clause(Node *clause) -{ - return (clause != NULL && - nodeTag(clause) == T_CaseExpr); -} /***************************************************************************** * * - * * + * General clause-manipulating routines * * * *****************************************************************************/ @@ -374,20 +358,21 @@ pull_constant_clauses(List *quals, List **constantQual) /* * clause_relids_vars - * Retrieves relids and vars appearing within a clause. - * Returns ((relid1 relid2 ... relidn) (var1 var2 ... varm)) where - * vars appear in the clause this is done by recursively searching - * through the left and right operands of a clause. - * - * Returns the list of relids and vars. + * Retrieves distinct relids and vars appearing within a clause. * + * '*relids' is set to an integer list of all distinct "varno"s appearing + * in Vars within the clause. + * '*vars' is set to a list of all distinct Vars appearing within the clause. + * Var nodes are considered distinct if they have different varno + * or varattno values. If there are several occurrences of the same + * varno/varattno, you get a randomly chosen one... */ void clause_get_relids_vars(Node *clause, Relids *relids, List **vars) { List *clvars = pull_var_clause(clause); - List *var_list = NIL; List *varno_list = NIL; + List *var_list = NIL; List *i; foreach(i, clvars) @@ -397,7 +382,7 @@ clause_get_relids_vars(Node *clause, Relids *relids, List **vars) Assert(var->varlevelsup == 0); if (!intMember(var->varno, varno_list)) - varno_list = lappendi(varno_list, var->varno); + varno_list = lconsi(var->varno, varno_list); foreach(vi, var_list) { Var *in_list = (Var *) lfirst(vi); @@ -407,7 +392,7 @@ clause_get_relids_vars(Node *clause, Relids *relids, List **vars) break; } if (vi == NIL) - var_list = lappend(var_list, var); + var_list = lcons(var, var_list); } freeList(clvars); @@ -424,22 +409,10 @@ clause_get_relids_vars(Node *clause, Relids *relids, List **vars) int NumRelids(Node *clause) { - List *vars = pull_var_clause(clause); - List *var_list = NIL; - List *i; - int result; + List *varno_list = pull_varnos(clause); + int result = length(varno_list); - foreach(i, vars) - { - Var *var = (Var *) lfirst(i); - - if (!intMember(var->varno, var_list)) - var_list = lconsi(var->varno, var_list); - } - - result = length(var_list); - freeList(vars); - freeList(var_list); + freeList(varno_list); return result; } @@ -468,7 +441,7 @@ is_joinable(Node *clause) * One side of the clause (i.e. left or right operands) must either be * a var node ... */ - if (IsA(leftop, Var) ||IsA(rightop, Var)) + if (IsA(leftop, Var) || IsA(rightop, Var)) return true; /* @@ -481,36 +454,6 @@ is_joinable(Node *clause) } /* - * qual_clause_p - * - * Returns t iff 'clause' is a valid qualification clause. - * - * For now we accept only "var op const" or "const op var". - */ -bool -qual_clause_p(Node *clause) -{ - Node *leftop, - *rightop; - - if (!is_opclause(clause)) - return false; - - leftop = (Node *) get_leftop((Expr *) clause); - rightop = (Node *) get_rightop((Expr *) clause); - - if (!rightop) - return false; /* unary opclauses need not apply */ - - /* How about Param-s ? - vadim 02/03/98 */ - if (IsA(leftop, Var) &&IsA(rightop, Const)) - return true; - if (IsA(rightop, Var) &&IsA(leftop, Const)) - return true; - return false; -} - -/* * fix_opids * Calculate opid field from opno for each Oper node in given tree. * (The given tree can be anything expression_tree_walker handles.) @@ -644,24 +587,16 @@ static int is_single_func(Node *node) { if (is_funcclause(node)) { - List *vars = pull_var_clause(node); + List *varnos = pull_varnos(node); - if (vars != NIL) + if (length(varnos) == 1) { - int funcvarno = ((Var *) lfirst(vars))->varno; - List *v; - /* need to check that all args of func are same relation */ - foreach(v, lnext(vars)) - { - if (((Var *) lfirst(v))->varno != funcvarno) - { - funcvarno = 0; - break; - } - } - freeList(vars); + int funcvarno = lfirsti(varnos); + + freeList(varnos); return funcvarno; } + freeList(varnos); } return 0; } |