On 4/25/15 12:12 AM, Amit Kapila wrote:
> ... which isn't possible. You can not go from a heap tuple to an
index tuple.
We will have the access to index value during delete, so why do you
think that we need linkage between heap and index tuple to perform
Delete operation? I think we need to think more to design Delete
.. by CTID, but that should be doable.
The problem with just having the value is that if *anything* changes
between how you evaluated the value when you created the index tuple and
when you evaluate it a second time you'll corrupt your index. This is
actually an incredibly easy problem to have; witness how we allowed
indexing timestamptz::date until very recently. That was clearly broken,
but because we never attempted to re-run the index expression to do
vacuuming at least we never corrupted the index itself.
> This has been discussed in the past.
I have tried to search in archive, but not getting what is the exact
problem.
Unfortunately I can't find prior discussion now either... :/
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com
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