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Fast default trigger and expand_tuple fixes

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Ensure that triggers get properly filled in tuples for the OLD value.
Also fix the logic of detecting missing null values. The previous logic
failed to detect a missing null column before the first missing column
with a default. Fixing this has simplified the logic a bit.

Regression tests are added to test changes. This should ensure better
coverage of expand_tuple().

Original bug reports, and some code and test scripts from Tomas Vondra

Backpatch to release 11.
This commit is contained in:
Andrew Dunstan
2018-09-24 16:11:24 -04:00
parent bfdd02f88b
commit 9625ab7924
4 changed files with 328 additions and 33 deletions
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51
src/backend/access/common/heaptuple.c
View File

@@ -823,44 +823,35 @@ expand_tuple(HeapTuple *targetHeapTuple,
{
if (attrmiss[firstmissingnum].am_present)
break;
else
hasNulls = true;
}
/*
* If there are no more missing values everything else must be NULL
* Now walk the missing attributes. If there is a missing value
* make space for it. Otherwise, it's going to be NULL.
*/
if (firstmissingnum >= natts)
for (attnum = firstmissingnum;
attnum < natts;
attnum++)
{
hasNulls = true;
}
else
{
/*
* Now walk the missing attributes. If there is a missing value
* make space for it. Otherwise, it's going to be NULL.
*/
for (attnum = firstmissingnum;
attnum < natts;
attnum++)
if (attrmiss[attnum].am_present)
{
if (attrmiss[attnum].am_present)
{
Form_pg_attribute att = TupleDescAttr(tupleDesc, attnum);
Form_pg_attribute att = TupleDescAttr(tupleDesc, attnum);
targetDataLen = att_align_datum(targetDataLen,
att->attalign,
att->attlen,
attrmiss[attnum].am_value);
targetDataLen = att_align_datum(targetDataLen,
att->attalign,
att->attlen,
attrmiss[attnum].am_value);
targetDataLen = att_addlength_pointer(targetDataLen,
att->attlen,
attrmiss[attnum].am_value);
}
else
{
/* no missing value, so it must be null */
hasNulls = true;
}
targetDataLen = att_addlength_pointer(targetDataLen,
att->attlen,
attrmiss[attnum].am_value);
}
else
{
/* no missing value, so it must be null */
hasNulls = true;
}
}
} /* end if have missing values */

5
src/backend/commands/trigger.c
View File

@@ -3396,7 +3396,10 @@ ltrmark:;
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
}
result = heap_copytuple(&tuple);
if (HeapTupleHeaderGetNatts(tuple.t_data) < relation->rd_att->natts)
result = heap_expand_tuple(&tuple, relation->rd_att);
else
result = heap_copytuple(&tuple);
ReleaseBuffer(buffer);
return result;