[frollogaston]

So you open transaction, insert multiple rows, commit? And you're not using any special xact settings like SERIALIZABLE mode, right? Normally you use COPY FROM if it's a huge number of rows in some batch process, but not like inserting a few rows handling a backend request or something.

I would try filling up the table, forcing a vacuum, then timing the inserts afterwards. Not that you should need to vacuum in real usage, but it might uncover a problem.

[daneel_w]

> So you open transaction, insert multiple rows, commit?

Pretty much, yes. High volume rapid multi-row INSERTs. Nothing special involved in the DDL or how the data goes into the table. Vacuuming the table (whether automatically or between every 10-20m rows) makes no difference. The indices still penalize the performance substantially the larger they grow.