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.tomonari@po.ntts.co.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@postgresql.org <pgsql-jdbc-owner@postgresql.org> on behalf of Tomonari Katsumata <katsumata.tomonari@po.ntts.co.jp>
> Sent: 21 February 2014 08:40
> To: pgsql-jdbc@postgresql.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$StatementResultHandler@8232a5d,
> maxRows=0, fetchSize=0, flags=16
> 14:09:55.878 (1) simple execute,
> handler=org.postgresql.jdbc2.AbstractJdbc2Statement$StatementResultHandler@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$StatementResultHandler@19cdbc83,
> maxRows=0, fetchSize=0, flags=48
> 14:20:34.992 (1) simple execute,
> handler=org.postgresql.jdbc2.AbstractJdbc2Statement$StatementResultHandler@304b0cbc,
> maxRows=0, fetchSize=0, flags=16
> ----
>
> This change has caused by below commit.
> https://github.com/pgjdbc/pgjdbc/commit/dbf76c2d662896c5703cf20d7362e1d061e1e43f
>
> 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
>
>
>
>
> --
> Sent via pgsql-jdbc mailing list (pgsql-jdbc@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-jdbc
>
>




--
Sent via pgsql-jdbc mailing list (pgsql-jdbc@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-jdbc