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From Kristian Waagan <kristian.waa...@oracle.com>
Subject Re: Performance Optimization for In-Memory ReadOnly Database
Date Tue, 24 May 2011 07:48:51 GMT
On 23.05.11 21:42, Stefan B├╝hlmann wrote:
> Hi together,
> I'm using derby for a dataprocessing application.
> SYSCS_UTIL.SYSCS_IMPORT_TABLE is used to import CSV data (around 100mb).
> The tables contain huge amount of rows (~100k) with some CLOB (max 60mb)
> columns.
> The table data is never altered (after the CSV import).
> Currently I'm using a in-memory database with pageCacheSize of 2000.
> Are there any other tricks to make querying the data more efficient?

Hi Stefan,

Do I understand you correctly if I say that you find the insert 
performance acceptable, but you find querying the inserted data too slow?

If so, is the data accessed by a single connection, or with multiple 
connections concurrently?
(i.e. can you run with a lower isolation level or use table locking?)
Have you created the relevant indexes?
Are you running a small set of queries repeatedly (using prepared 
statements), or performing "ad-hoc" queries?

It may be good to post some of the DDL and the queries which perform poorly.


> Kind Regards
> Stefan

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