On Mon, Mar 14, 2011 at 4:17 AM, Marti Raudsepp
<marti@juffo.org> wrote:
> Other than being very inefficient, and consuming
> more time than necessary, is there any other down side to importing
> into an indexed table?
Doing so will result in somewhat larger (more bloated) indexes, but
generally the performance impact of this is minimal.
Bulk data imports of this size I've done with minimal pain by simply breaking the raw data into chunks (10M records becomes 10 files of 1M records), on a separate spindle from the database, and performing multiple COPY commands but no more than 1 COPY per server core. I tested this a while back on a 4 core server and when I attempted 5 COPY's at a time the time to complete went up almost 30%. I don't recall any benefit having fewer than 4 in this case but the server was only processing my data at the time. Indexes were on the target table however I dropped all constraints. The UNIX split command is handy for breaking the data up into individual files.
Greg