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PostgreSQL autovacuum

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Question:
 I have a database where I virtually never delete and almost never do
updates. (The updates might change in the future but for now it's okay to
assume they never happen.) As such, it seems like it might be worth it to
set autovacuum=off or at least make it so vacuuming hardly ever occurs.
Actually, the latter is probably the more robust solution, though I don't
know how to do that (hence me writing this list). I did try turning
autovacuum off but got:

 ERROR: parameter "autovacuum" cannot be changed now
 SQL state: 55P02

 Not sure what, if anything, I can do about that.
Answer:
Autovacuum is controlled by how much of a table has changed, so if a
table never changes, it never gets vacuumed (with the exceptional case
being a forced vacuum freeze to mitigate the transaction id
 wrap-around issue).  The settings which control this are
autovacuum_vacuum_threshold and autovacuum_vacuum_scale_**factor.
Therefore it isn't necessary to disable autovacuum.

 But if you are adamant about disabling it, you need to change it in
your postgresql.conf file and restart the server.

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