Re: INSERT performance deteriorates quickly during a large import

"Krasimir Hristozov \(InterMedia Ltd\)" <krasi@imedia-dev.com> writes:
> We need to import data from a relatively large MySQL database into an
> existing PostgreSQL database, using a PHP5 script that SELECTs from MySQL
> and INSERTs in PostgreSQL. A part of the import involves moving about
> 1,300,000 records from one MySQL table to one of our PostgreSQL tables. The
> problem is that the insert performance inevitably deteriorates as the number
> of inserts increases.

Are you *certain* you've gotten rid of all the indexes and foreign keys?
A simple insert ought to be pretty much constant-time in Postgres, so it
seems to me that you've missed something.

It also seems possible that you are wrong to disregard PHP as a possible
source of the problem.  Have you tried watching the PHP and PG backend
processes with "top" (or similar tool) to see who's consuming CPU time
and/or memory space?

            regards, tom lane