perf pb solved only after pg_dump and restore

Hi,

We noticed a slowdown on our application while traffic was kinda
heavy. The logics after reading the docs commanded us to trim the
enlarged tables, run VACUUM ANALYZE and then expect fast
performance again; but it wasn't the case[1].

Out of the blue, we dumped the database, removed it, recreated
from the restore, and now the performance is lightning fast
again.

Does it look familiar to anyone? I thought running VACUUM ANALYZE
after a trim should be enough so that pg has assembled the data
and has good statistical knowledge of the tables contents..

Thanks for any tips.

Ref:
[1] Processes were always showing one/some postmaster on SELECT,
a constant load of 1, and vmstat always showing activity in
IO blocks out (application generate all sort of typical
statements, some SELECT, UPDATE, INSERT either "directly" or
through stored procedures)

--
Guillaume Cottenceau
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