On Sun, Apr 23, 2017 at 10:33 PM, Tatsuo Ishii <is...@sraoss.co.jp> wrote:
> > Andres Freund <and...@anarazel.de> writes: > >> On 2017-04-23 12:08:51 -0700, Konstantin Izmailov wrote: > >>> Some systems (Presto) are still using protocol 2, and I need to > understand > >>> the scope of changes in the middleware to support protocol 2. > > > >> Could you provide a reference about presto using v2 protocol? A quick > >> search didn't turn anything up. Presto seems a bit too new to rely on > >> v2, given how long ago v3 has been introduced. > > > > There's been moderately serious discussion about dropping v2 support > > altogether, so I sure hope there isn't anything in the wild that still > > depends on it. > > > > Also, moving from v2 to v3 per se just isn't very hard, if you aren't > > worried about making use of new-in-v3 protocol features. I wonder > whether > > Konstantin is confusing v2 vs v3 with use of simple vs. extended query > > protocol within v3. > > It seems Presto uses v3 protocol only when ODBC driver is used. If > JDBC is used, it is required to set "protocolVersion=2" property of > JDBC driver, which means v2 protocol is used I think. > > https://github.com/treasure-data/prestogres#limitation > > As Tom mentioned, it sounds like the issue is that Presto expects to only use simple query, not extended query (no server-side prepared statements). The JDBC driver supports setting the prepare threshold to 0 to disable using server-side prepares. https://jdbc.postgresql.org/documentation/publicapi/org/postgresql/PGStatement.html#setPrepareThreshold-int- "If threshold is zero, server-side prepare will not be used." > Best regards, > -- > Tatsuo Ishii > SRA OSS, Inc. Japan > English: http://www.sraoss.co.jp/index_en.php > Japanese:http://www.sraoss.co.jp > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >
