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Add support for NullIfExpr in eval_const_expressions

Author: Hou Zhijie <houzj.fnst@cn.fujitsu.com>
Discussion: https://www.postgresql.org/message-id/flat/7ea5ce773bbc4eea9ff1a381acd3b102@G08CNEXMBPEKD05.g08.fujitsu.local
This commit is contained in:
Peter Eisentraut
2021-04-02 11:01:49 +02:00
parent 96bdb7e19d
commit 9c5f67fd62
3 changed files with 66 additions and 0 deletions

View File

@@ -2497,6 +2497,36 @@ eval_const_expressions_mutator(Node *node,
newexpr->location = expr->location;
return (Node *) newexpr;
}
case T_NullIfExpr:
{
NullIfExpr *expr;
ListCell *arg;
bool has_nonconst_input = false;
/* Copy the node and const-simplify its arguments */
expr = (NullIfExpr *) ece_generic_processing(node);
/* If either argument is NULL they can't be equal */
foreach(arg, expr->args)
{
if (!IsA(lfirst(arg), Const))
has_nonconst_input = true;
else if (((Const *) lfirst(arg))->constisnull)
return (Node *) linitial(expr->args);
}
/*
* Need to get OID of underlying function before checking if
* the function is OK to evaluate.
*/
set_opfuncid((OpExpr *) expr);
if (!has_nonconst_input &&
ece_function_is_safe(expr->opfuncid, context))
return ece_evaluate_expr(expr);
return (Node *) expr;
}
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *saop;