Re: Caching - Mailing list pgsql-jdbc

From Fernando Nasser
Subject Re: Caching
Date
Msg-id 3F53D1F6.1020303@redhat.com
Whole thread Raw
In response to Caching  ("Lufkin, Brad" <brad.lufkin@ngc.com>)
List pgsql-jdbc
If you write:

setUseServerPrepare(true)

for a PreparedStatement the driver will try and ask the backend to keep
a parse tree of it for repeated use by the client (if supported).

But if you can keep your stuff in a transaction and avoid using server
side prepared statements you'll get a better performance (the
optimization may not be so good done in advance as it does not have all
the info).

Regards,
Fernando

snpe wrote:
> What is server side prepared statement and how I used it in jdbc ?
>
> Thanks
> Haris Peco
> On Friday 29 August 2003 09:35 pm, Fernando Nasser wrote:
>
>>Yes, the current driver has setFetchSize() implemented.
>>
>>Note that you must be inside a transaction as a cursor is used for
>>implementing this.  Alternatively you can be using a server side prepared
>>statement (you don't need to be inside a transaction in that case).
>>
>>If you are using an older driver, you can always declare a cursor yourself.
>>
>>Regards,
>>Fernando
>>
>>Lufkin, Brad wrote:> Whenever I execute a query and retrieve the results
>>with
>>
>>the sequence:
>>
>>>    ResultSet resultSet = statement.executeQuery("SELECT blah blah
>>>blah...");
>>>    while (resultSet.next()) {
>>>        //do something with the resultSet
>>>    }
>>>
>>>it looks like the query is completely carried out before any results are
>>>returned. This contrasts with the behavior of other databases (Informix
>>>comes to mind) where the query returns immediately and the results are
>>>returned as the database fetches them. Is my supposition correct, and, if
>>>so, is there any way to make postgres behave the same way as Informix?
>>>My reasons for wanting this behavior is that I'm displaying results in
>>>real time to a user through a GUI and the gradual display of results is
>>>preferable to a long pause followed by all the results at once.
>>>
>>>---------------------------(end of broadcast)---------------------------
>>>TIP 5: Have you checked our extensive FAQ?
>>>
>>>               http://www.postgresql.org/docs/faqs/FAQ.html
>>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 8: explain analyze is your friend
>


--
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9


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