Re: Running update in chunks?

Tim Uckun wrote:

> If you have any suggestions I am all ears. For the purposes of this
> discussion we can narrow down the problem this update statement.
> 
> Update imports set make_id = null.

Well, that simplifies things.

First off, what does it say for rows affected? (Hint, if you really
are using a default configuration and it doesn't say 0 rows
affected, please show us the actual query used.)

Second, try connecting to the database as a superuser and running:

VACUUM ANALYZE imports;
-- (show us the results)
VACUUM FULL imports;
VACUUM FREEZE ANALYZE;  -- (don't specify a table)

Then try your query and see whether performance is any different.

-Kevin