Re: using index or check in ALTER TABLE SET NOT NULL

Hello

> Do you actually need test output proving that this code path was taken
> rather than the default one? Seems like looking at the code coverage
> report might be enough.
I not known. In v4 i use DEBUG1 message and do not check code path in tests at all: by full table scan or by constraint, i tested only command result to not break behavior.
Today Ildar Musin proposed to test code path through NotNullImpliedByRelConstraints function. This is my first patch and I do not have the confidence to write a test. So I looked more closely at the alter table tests, found several info in attach partition and updated my patch.

> I did not see any INFO messages in a quick test of ALTER TABLE ATTACH
> PARTITION, but if there are any lurking in there, they probably need
> to be downgraded.
In src/test/regress/expected/alter_table.out i found 7 test with
> INFO: partition constraint for table "..." is implied by existing constraints
and 5 with
> INFO:  updated partition constraint for default partition "..." is implied by existing constraints
ereport's are in ValidatePartitionConstraints function src/backend/commands/tablecmds.c

regards, Sergei