Re: query performance, though it was timestamps,maybe just table size? - Mailing list pgsql-general

From Kevin Grittner
Subject Re: query performance, though it was timestamps,maybe just table size?
Date
Msg-id 20121130182347.69290@gmx.com
Whole thread Raw
Responses Re: query performance, though it was timestamps,maybe just table size?  (Henry Drexler <alonup8tb@gmail.com>)
List pgsql-general
Henry Drexler wrote:

> why would the query time go from 4 minutes to over 50, for an
> increase in table rows from 30 million to 65 million?

Did the active (frequently referenced) portion of the database go
from something which fit in cache to something which didn't? Did
any hash table or sort nodes in plans go from fitting in work_mem
to spilling to disk? Did any indexes need an extra level in the
tree? Did any plans change based on size to something which is less
than optimal, suggesting a need to tune the cost factors?

-Kevin


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