Peter Eisentraut <pete...@gmx.net> wrote: > Therefore, it cannot be completely unexpected if column triggers are > called even if the column was not actually changed in a semantically > significant way.
Ok, the attached patch implements standard-compliant version of
column trigger.
Retrieving modified columns is not so difficult as I expected.
It is in:
rt_fetch(relinfo->ri_RangeTableIndex, estate->es_range_table)->modifiedCols
and the information are passed from caller to trigger routines.
However, to be honest, I think standard-compliant column trigger is
useless... I'm thinking additional extension for triggers -- if we
want to check modifications of actual values, it could be defined as:
CREATE TRIGGER trig BEFORE UPDATE ON tbl FOR EACH ROW
WHEN (NEW.col <> OLD.col) EXECUTE PROCEDURE trigger_func();
Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center
standard-column-trigger-20090907.patch
Description: Binary data
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