From: | Oliver Jowett <oliver(at)opencloud(dot)com> |
---|---|
To: | John Lister <john(dot)lister(at)kickstone(dot)com> |
Cc: | Dave Cramer <pg(at)fastcrypt(dot)com>, Péter Kovács <maxottovonstirlitz(at)gmail(dot)com>, Frédérik Bilhaut <frederik(dot)bilhaut(at)noopsis(dot)fr>, pgsql-jdbc(at)postgresql(dot)org |
Subject: | Re: Very strange performance decrease when reusing a PreparedStatement |
Date: | 2009-05-03 23:28:23 |
Message-ID: | 49FE2897.3020802@opencloud.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-jdbc |
John Lister wrote:
> However it seems that other optimisations can't be made for example it
> doesn't seem possible to tell the server that parameter 1 is always
> going to be an int and therefore it should be using index A. The current
> implementation may not use index A as it is unaware as to the type of
> the supplied parameter. Perhaps in this case the execution planner
> should pick the parameters for the most optimal plan and return the
> types during the parse and let the driver convert the data to what the
> server requires...
No it's not a problem with types at all, parameter types are fixed at
the point the named statement is created.
It's all about index selectivity statistics.
-O
From | Date | Subject | |
---|---|---|---|
Next Message | Oliver Jowett | 2009-05-03 23:43:23 | Re: Very strange performance decrease when reusing a PreparedStatement |
Previous Message | Roland Roberts | 2009-05-03 23:12:21 | Re: Very strange performance decrease when reusing a PreparedStatement |