Reconsider old decision to try to constant-fold default and constraint

expressions before they are stored.  This seems like not such a hot idea,
particularly now that the constant-folder will try to inline SQL functions.
This commit is contained in:
Tom Lane 2003-01-08 22:06:23 +00:00
parent 51d2e3bd6e
commit 2d140d35a4
3 changed files with 8 additions and 20 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.238 2002/12/16 18:39:22 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.239 2003/01/08 22:06:20 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -1604,11 +1604,6 @@ AddRelationRawConstraints(Relation rel,
if (contain_agg_clause(expr))
elog(ERROR, "cannot use aggregate function in CHECK constraint expression");
/*
* Might as well try to reduce any constant expressions.
*/
expr = eval_const_expressions(expr);
/*
* Constraints are evaluated with execQual, which expects an
* implicit-AND list, so convert expression to implicit-AND form.
@ -1733,7 +1728,7 @@ cookDefault(ParseState *pstate,
* column's type. We store the expression without coercion, however,
* to avoid premature coercion in cases like
*
* CREATE TABLE tbl (fld timestamp DEFAULT 'now'::text);
* CREATE TABLE tbl (fld timestamp DEFAULT 'now');
*
* NB: this should match the code in rewrite/rewriteHandler.c that will
* actually do the coercion, to ensure we don't accept an unusable
@ -1755,11 +1750,6 @@ cookDefault(ParseState *pstate,
format_type_be(type_id));
}
/*
* Might as well try to reduce any constant expressions.
*/
expr = eval_const_expressions(expr);
return (expr);
}

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.64 2002/12/30 19:45:17 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.65 2003/01/08 22:06:23 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2756,7 +2756,10 @@ AlterTableAddCheckConstraint(Relation rel, Constraint *constr)
elog(ERROR, "cannot use aggregate function in CHECK constraint expression");
/*
* Might as well try to reduce any constant expressions.
* Might as well try to reduce any constant expressions, so as to
* minimize overhead while testing the constraint at each row.
*
* Note that the stored form of the constraint will NOT be const-folded.
*/
expr = eval_const_expressions(expr);

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/typecmds.c,v 1.28 2003/01/08 21:40:39 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/typecmds.c,v 1.29 2003/01/08 22:06:23 tgl Exp $
*
* DESCRIPTION
* The "DefineFoo" routines take the parse tree and pick out the
@ -1623,11 +1623,6 @@ domainAddConstraint(Oid domainOid, Oid domainNamespace, Oid baseTypeOid,
if (contain_agg_clause(expr))
elog(ERROR, "cannot use aggregate function in CHECK constraint expression");
/*
* Might as well try to reduce any constant expressions.
*/
expr = eval_const_expressions(expr);
/*
* Convert to string form for storage.
*/