Hi,
A few years back, I analysed the reason why some JDBC requests
were slower than psql requests. It turned out that, by using
prepared statement in protocol v3, the query plan is determined
once and for all (IIRC, for a given PreparedStatement object),
and so when reused later with other query parameters (typically,
not as selective, I guess), it turned out to be much slower
(suboptimal query plan). The only workaround I found back then,
was to use protocol v2 (IIRC prepared statements are fully client
side in protocol v2?). I noticed recently though that it's not
going to be able anymore soon, because the 9.5 backend breaks on
the driver passing autocommit=true anyways.
Thanks
> Hi,
>
> Does anybody still use v2 protocol via pgjdbc?
>
> I'm reworking QueryExecutor/ProcotolConnection implementation as a part of
> "smarter returning" (https://github.com/pgjdbc/pgjdbc/issues/488), and I would
> like to just drop v2 support.
>
> As far as I know, v3 was introduced in PostgreSQL 7.4, thus it looks rather
> safe to just drop v2 support in pjgdbc.
>
> By the way, the oldest version we test in Travis is 8.4
>
> Vladimir
--
Guillaume Cottenceau
