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Pass collation to makeConst() instead of looking it up internally.

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In nearly all cases, the caller already knows the correct collation, and
in a number of places, the value the caller has handy is more correct than
the default for the type would be.  (In particular, this patch makes it
significantly less likely that eval_const_expressions will result in
changing the exposed collation of an expression.)  So an internal lookup
is both expensive and wrong.
This commit is contained in:
Tom Lane
2011-03-25 20:10:42 -04:00
parent c8e993503d
commit bfa4440ca5
18 changed files with 165 additions and 56 deletions
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40
src/backend/utils/adt/selfuncs.c
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@ -1686,6 +1686,7 @@ scalararraysel(PlannerInfo *root,
Node *leftop;
Node *rightop;
Oid nominal_element_type;
Oid nominal_element_collation;
RegProcedure oprsel;
FmgrInfo oprselproc;
Selectivity s1;
@ -1712,6 +1713,8 @@ scalararraysel(PlannerInfo *root,
nominal_element_type = get_base_element_type(exprType(rightop));
if (!OidIsValid(nominal_element_type))
return (Selectivity) 0.5; /* probably shouldn't happen */
/* get nominal collation, too, for generating constants */
nominal_element_collation = exprCollation(rightop);
/* look through any binary-compatible relabeling of rightop */
rightop = strip_array_coercion(rightop);
@ -1759,6 +1762,7 @@ scalararraysel(PlannerInfo *root,
args = list_make2(leftop,
makeConst(nominal_element_type,
-1,
nominal_element_collation,
elmlen,
elem_values[i],
elem_nulls[i],
@ -5616,9 +5620,39 @@ static Const *
string_to_const(const char *str, Oid datatype)
{
Datum conval = string_to_datum(str, datatype);
Oid collation;
int constlen;
return makeConst(datatype, -1,
((datatype == NAMEOID) ? NAMEDATALEN : -1),
/*
* We only need to support a few datatypes here, so hard-wire properties
* instead of incurring the expense of catalog lookups.
*/
switch (datatype)
{
case TEXTOID:
case VARCHAROID:
case BPCHAROID:
collation = DEFAULT_COLLATION_OID;
constlen = -1;
break;
case NAMEOID:
collation = InvalidOid;
constlen = NAMEDATALEN;
break;
case BYTEAOID:
collation = InvalidOid;
constlen = -1;
break;
default:
elog(ERROR, "unexpected datatype in string_to_const: %u",
datatype);
return NULL;
}
return makeConst(datatype, -1, collation, constlen,
conval, false, false);
}
@ -5635,7 +5669,7 @@ string_to_bytea_const(const char *str, size_t str_len)
SET_VARSIZE(bstr, VARHDRSZ + str_len);
conval = PointerGetDatum(bstr);
return makeConst(BYTEAOID, -1, -1, conval, false, false);
return makeConst(BYTEAOID, -1, InvalidOid, -1, conval, false, false);
}
/*-------------------------------------------------------------------------