On Fri, Jul 05, 2019 at 03:28:26PM +0300, Nikolay Shaplov wrote:
I am importing recent changes into my reloption patch and came to a question,
I did not find an answer...
vacuum_index_cleanup option exists for both heap and toast relations.
As I understand from documentation index cleanup is about is about reporting
access method that some tuples in table that were indexed are dead, and should
be cleaned.
And as far as I get, we do not index any TOAST tuples directly. They are
obtained by getting relation tuple, and then deTOAST it.
So I do not understand why do we need vacuum_index_cleanup for TOAST tables.
May be we should remove it from there??
Or if I am wrong, can you explain where it is needed?
I'm not sure I understand your question / suggestion correctly, but
each TOAST table certainly has an index on (chunk_id, chunk_seq) - in
fact it's a unique index backing a primary key.
It's not clear to me what you mean by "index any TOAST tuples directly"
or "getting relation tuple", perhaps you could explain.
IMHO it's correct to have vacuum_index_cleanup even for TOAST tables.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
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