Home > Archive > PostgreSQL Discussion > April 2005 > Re: What does "tuple concurrently updated" mean?









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Author Re: What does "tuple concurrently updated" mean?
Tom Lane

2005-04-25, 11:23 am

"Florian G. Pflug" <fgp@phlo.org> writes:
> During a batch load of records (using COPY) I got the following
> postgres error today "tuple concurrently updated".


I don't think plain COPY could have produced that, since it only inserts
tuples. Tell us about triggers and foreign keys on this table?

regards, tom lane

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Tom Lane

2005-04-25, 1:23 pm

"Florian G. Pflug" <fgp@phlo.org> writes:
> So - does "tuple concurrently updated" make sense for "analyze"?


Yeah, it's entirely possible, if you have a background process that
might issue analyzes too (do you use autovacuum?). The error comes when
two sessions concurrently try to update the same row in pg_statistic.
I've looked at preventing it, but the cure seems worse than the disease
--- we don't really want ANALYZE to take any strong locks on the table,
and in any case all you are losing is presumably-near-duplicate stats
from one session or the other.

regards, tom lane

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