Hi,
BuildTupleFromCStrings() has comment "/* Call the "in" function for
each non-dropped attribute */". It then calls the in function even
when it's going to set that attribute to NULL.
1189 if (!TupleDescAttr(tupdesc, i)->attisdropped)
1190 {
1191 /* Non-dropped attributes */
1192 dvalues[i] = InputFunctionCall(&attinmeta->attinfuncs[i],
1193 values[i],
1194 attinmeta->attioparams[i],
1195 attinmeta->atttypmods[i]);
1196 if (values[i] != NULL)
1197 nulls[i] = false;
1198 else
1199 nulls[i] = true;
1200 }
If we are setting isnull to true i.e. it's a NULL value, dvalues
value doesn't matter but we still invoke corresponding in function,
which looks strange and the comment doesn't help. But there's code in
make_tuple_from_result_row() which does the same thing and explain why
we need to invoke in() function even on the NULL values. I thought,
the same comment applies here. Here's patch to update the comment in
BuildTupleFromCStrings().
The code in make_tuple_from_result_row() that converts an array of
values string to tuple looks quite similar to what
BuildTupleFromCStrings() is doing with a small difference that
make_tuple_from_result_row() maintains and error context to report the
attribute whose in() function caused an error. May be we could pass an
optional error context to the later and use it.
--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company
From c8faf979d34a04099597bdbbe952ca7a936e5dbe Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.ba...@enterprisedb.com>
Date: Fri, 23 Mar 2018 14:37:46 +0530
Subject: [PATCH] Comment fix in BuildTupleFromCStrings()
Explain in what case we need to invoke in() function even when the
value string is NULL in BuildTupleFromCStrings().
Ashutosh Bapat
---
src/backend/executor/execTuples.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/backend/executor/execTuples.c b/src/backend/executor/execTuples.c
index c46d65c..5089b7f 100644
--- a/src/backend/executor/execTuples.c
+++ b/src/backend/executor/execTuples.c
@@ -1183,7 +1183,10 @@ BuildTupleFromCStrings(AttInMetadata *attinmeta, char **values)
dvalues = (Datum *) palloc(natts * sizeof(Datum));
nulls = (bool *) palloc(natts * sizeof(bool));
- /* Call the "in" function for each non-dropped attribute */
+ /*
+ * Call the "in" function for each non-dropped attribute, even for nulls,
+ * to support domains.
+ */
for (i = 0; i < natts; i++)
{
if (!TupleDescAttr(tupdesc, i)->attisdropped)
--
1.7.9.5
