Thread: Trying to Tunning DB

Trying to Tunning DB

From
"Cristina Surroca"
Date:

Hi,

 

    I'm doing a project and I've have some problems.

    My table has (ID, atr1,..., atn), but there isn't any primary key because of the specifications, it's very similar to a Data warehouse, where every event is stored. It hasn't any delete, only inserts (more than 10^7) and many updates.

    The thing is that it takes too much time in execute. (In my case, before each update I've to do select to find which row I have to modify, and I suppose it does a table scan. To improve it, I've thought to use a Btree for ID column).

    I use JDBC. To make it works better, I use:

  •  Prepared Statements
  • setAutocommit(false), ( in my case I don't need transactions).
  • I'm been reading PostgreSQL mailing list archive to try to discover other kinds of "tune", or how to improve it.
  • I've also read FAQ and I've found "3.6) How do I tune the data base engine for better performance". 

    But in my case, would you think vacuum and analyze are good options? Can I do everything else? Can I  also disable the catalog?

 

Thanks a lot

 

yours,

 

 

Cris..

 

Re: Trying to Tunning DB

From
Manfred Koizar
Date:
On Sat, 5 Apr 2003 16:15:37 +0200, "Cristina Surroca" <cris@dmcid.net>
wrote:
> It hasn't any delete, only inserts (more than 10^7) and many updates.

10^7 inserts per day?  If it has updates, it implicitly has deletes.
How *many* updates?

>    The thing is that it takes too much time in execute.

We can help you better, if you show us some actual SQL.

>  b.. setAutocommit(false), ( in my case I don't need transactions).

There is no I_dont_need_transactions mode in Postgres.  You always
have transactions.  Either you control them or Postgres performs each
statement in its own transaction.  As far as I understand, autocommit
off means that you don't have to say BEGIN to start a transaction and
the transaction stays active until you COMMIT.  Your application or
JDBC might do this automatically.

>    But in my case, would you think vacuum and analyze are good options?

Definitely!

> Can I  also disable the catalog?

I don't know what you mean, but I am pretty sure, you can't.

Servus
 Manfred