John, On 7/26/05 9:56 AM, "John A Meinel" <[EMAIL PROTECTED]> wrote:
> You could insert all of your data into a temporary table, and then do: > > INSERT INTO final_table SELECT * FROM temp_table WHERE NOT EXISTS > (SELECT info FROM final_table WHERE id=id, path=path, y=y); > > Or you could load it into the temporary table, and then: > DELETE FROM temp_table WHERE EXISTS (SELECT FROM final_table WHERE id...); > > And then do a plain INSERT INTO. > > I can't say what the specific performance increases would be, but > temp_table could certainly be an actual TEMP table (meaning it only > exists during the connection), and you could easily do a COPY into that > table to load it up quickly, without having to check any constraints. Yah - that's a typical approach, and it would be excellent if the COPY bypassed WAL for the temp table load. This is something we discussed in bizgres development a while back. I think we should do this for sure - would nearly double the temp table load rate, and the subsequent temp table delete *should* be fast enough (?) Any performance tests you've done on that delete/subselect operation? - Luke ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
