> > I noticed in 8.3 there are chances where we can avoid WAL logging. For
> > example, 8.3's pgbench was modified to use TRUNCATE right before
> > COPY. Is there any documentation which describes that kind of
> > techniques? If there's none, I would volunteer the work to create such
> > a documentation since I think this is valuable information for DBAs
> > who wish to migrate to 8.3.
>
> The Performance Tips section has been modified to describe this. Would
> you like me to add something elsewhere also? Multiple entry points to
> information helps everybody, so I'll happily add more.
Thanks for pointing out. I found following:
"COPY is fastest when used within the same transaction as an earlier
CREATE TABLE or TRUNCATE command. In such cases no WAL needs to be
written, because in case of an error, the files containing the newly
loaded data will be removed anyway."
Sounds great!
BTW, I noticed that "COPY, CLUSTER, B-Tree split logging improvements"
in Josh's presentation in Tokyo. Are they just internal changes and
are nothing to do with DBA's job?
--
Tatsuo Ishii
SRA OSS, Inc. Japan