Re: About binaryTransfer.

Please submit a Pull Request

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca

On Fri, Feb 21, 2014 at 3:57 AM, Tomonari Katsumata <
katsumata(dot)tomonari(at)po(dot)ntts(dot)co(dot)jp> wrote:

> Hi Mikko,
>
> Thank you for the explanation.
>
> I agree with your proposal adding prepareThreshold=-1.
>
> If there are no objection, I'll do for it!
>
> regards,
> ----------------
> Tomonari Katsumata
>
>
> (2014/02/21 16:50), Mikko Tiihonen wrote:
> > Before the patch the functionality was (if binaryTransfer=true):
> > - prepared statements after prepareThreshold were done in binary mode
> > - forceBinary=true could be enabled to force all statements (prepared +
> one-shot) to be executed in binary mode (at cost of extra round-trip)
> >
> > After the patch in question (if binaryTransfer=true):
> > - All prepared statements have extra round-trip before on first use and
> are immediately in binary mode
> > - forceBinary=true can be enabled to force also one-shot statements to
> be executed in binary mode (at cost of extra round-trip)
> >
> > Since there are users that use prepared statements in one-shot way
> (prepare+execute+discard) the patch adds a mandatory extra round-trip for
> them.
> >
> > As a side note: the forceBinary is meant only as a debug flag (used for
> example in pgjdbc tests), not for production use.
> >
> > So the only thing the before-state could not do was to use binary
> transfers for the first prepared statement execution. This is because
> setting prepareThreshold=0 disables the prepare instead of preparing before
> first use.
> >
> > I propose we revert that patch and instead add support for
> prepareThreshold=-1 which would force prepare+describe to be done even for
> the first execution. That would allow users to keep controlling the
> behavior instead of forcing binary transfers immediately?
> > Alternatively we can separate the binary transfer logic from statement
> prepare threshold and add a separate binaryThreshold.
> >
> > -Mikko
> > ________________________________________
> > From: pgsql-jdbc-owner(at)postgresql(dot)org <pgsql-jdbc-owner(at)postgresql(dot)org>
> on behalf of Tomonari Katsumata <katsumata(dot)tomonari(at)po(dot)ntts(dot)co(dot)jp>
> > Sent: 21 February 2014 08:40
> > To: pgsql-jdbc(at)postgresql(dot)org
> > Subject: [JDBC] About binaryTransfer.
> >
> > Hi,
> >
> > I have a peformance trouble with 9.3-1100 driver.
> > Running same application(*) with 9.2-1004 and 9.3-1100,
> > It does another behavior.
> > (*) Retrieving 9990 rows with preparedStatement.
> >
> > 9.2-1004:
> > Always flags = 16.
> > ----
> > 14:09:55.730 (1) simple execute,
> > handler=org.postgresql.jdbc2.AbstractJdbc2Statement$
> StatementResultHandler(at)8232a5d,
> > maxRows=0, fetchSize=0, flags=16
> > 14:09:55.878 (1) simple execute,
> > handler=org.postgresql.jdbc2.AbstractJdbc2Statement$
> StatementResultHandler(at)34e671de,
> > maxRows=0, fetchSize=0, flags=16
> > ----
> >
> > 9.3-1100
> > Repeatedly flags = 48 and 16.
> > The count of "flags=16" is same with 9.2-1004, so
> > "flags=48" is extra executing.
> > ----
> > 14:20:34.991 (1) simple execute,
> > handler=org.postgresql.jdbc2.AbstractJdbc2Statement$
> StatementResultHandler(at)19cdbc83,
> > maxRows=0, fetchSize=0, flags=48
> > 14:20:34.992 (1) simple execute,
> > handler=org.postgresql.jdbc2.AbstractJdbc2Statement$
> StatementResultHandler(at)304b0cbc,
> > maxRows=0, fetchSize=0, flags=16
> > ----
> >
> > This change has caused by below commit.
> > https://github.com/pgjdbc/pgjdbc/commit/dbf76c2d662896c5703cf20d7362e1
> d061e1e43f
> >
> > It seems that binarytransfer mode is good at dealing with
> > big-data(many columns?many rows?), but some packets are
> > sent/received for this function, right?
> >
> > I want to make 9.3-1100 driver do old behavior like 9.2-1004.
> > What can I do ?
> >
> > regards,
> > ----------------
> > Tomonari Katsumata
> >
> >
> >
> >
> > --
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> >
> >
>
>
>
>
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