|
8 | 8 | * |
9 | 9 | * |
10 | 10 | * IDENTIFICATION |
11 | | - * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.258 2008/05/12 00:00:49alvherre Exp $ |
| 11 | + * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.259 2008/05/15 17:37:49tgl Exp $ |
12 | 12 | * |
13 | 13 | * HISTORY |
14 | 14 | * AUTHORDATEMAJOR EVENT |
@@ -2106,6 +2106,71 @@ eval_const_expressions_mutator(Node *node, |
2106 | 2106 | return (Node*)newrelabel; |
2107 | 2107 | } |
2108 | 2108 | } |
| 2109 | +if (IsA(node,CoerceViaIO)) |
| 2110 | +{ |
| 2111 | +CoerceViaIO*expr= (CoerceViaIO*)node; |
| 2112 | +Expr*arg; |
| 2113 | +Oidoutfunc; |
| 2114 | +boolouttypisvarlena; |
| 2115 | +Oidinfunc; |
| 2116 | +Oidintypioparam; |
| 2117 | +Expr*simple; |
| 2118 | +CoerceViaIO*newexpr; |
| 2119 | + |
| 2120 | +/* |
| 2121 | + * Reduce constants in the CoerceViaIO's argument. |
| 2122 | + */ |
| 2123 | +arg= (Expr*)eval_const_expressions_mutator((Node*)expr->arg, |
| 2124 | +context); |
| 2125 | + |
| 2126 | +/* |
| 2127 | + * CoerceViaIO represents calling the source type's output function |
| 2128 | + * then the result type's input function. So, try to simplify it |
| 2129 | + * as though it were a stack of two such function calls. First we |
| 2130 | + * need to know what the functions are. |
| 2131 | + */ |
| 2132 | +getTypeOutputInfo(exprType((Node*)arg),&outfunc,&outtypisvarlena); |
| 2133 | +getTypeInputInfo(expr->resulttype,&infunc,&intypioparam); |
| 2134 | + |
| 2135 | +simple=simplify_function(outfunc, |
| 2136 | +CSTRINGOID,-1, |
| 2137 | +list_make1(arg), |
| 2138 | + true,context); |
| 2139 | +if (simple)/* successfully simplified output fn */ |
| 2140 | +{ |
| 2141 | +/* |
| 2142 | + * Input functions may want 1 to 3 arguments. We always supply |
| 2143 | + * all three, trusting that nothing downstream will complain. |
| 2144 | + */ |
| 2145 | +List*args; |
| 2146 | + |
| 2147 | +args=list_make3(simple, |
| 2148 | +makeConst(OIDOID,-1,sizeof(Oid), |
| 2149 | +ObjectIdGetDatum(intypioparam), |
| 2150 | +false, true), |
| 2151 | +makeConst(INT4OID,-1,sizeof(int32), |
| 2152 | +Int32GetDatum(-1), |
| 2153 | +false, true)); |
| 2154 | + |
| 2155 | +simple=simplify_function(infunc, |
| 2156 | +expr->resulttype,-1, |
| 2157 | +args, |
| 2158 | + true,context); |
| 2159 | +if (simple)/* successfully simplified input fn */ |
| 2160 | +return (Node*)simple; |
| 2161 | +} |
| 2162 | + |
| 2163 | +/* |
| 2164 | + * The expression cannot be simplified any further, so build and |
| 2165 | + * return a replacement CoerceViaIO node using the possibly-simplified |
| 2166 | + * argument. |
| 2167 | + */ |
| 2168 | +newexpr=makeNode(CoerceViaIO); |
| 2169 | +newexpr->arg=arg; |
| 2170 | +newexpr->resulttype=expr->resulttype; |
| 2171 | +newexpr->coerceformat=expr->coerceformat; |
| 2172 | +return (Node*)newexpr; |
| 2173 | +} |
2109 | 2174 | if (IsA(node,CaseExpr)) |
2110 | 2175 | { |
2111 | 2176 | /*---------- |
|