On 23.05.11 21:42, Stefan Bühlmann 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.
Regards,
--
Kristian
Kind Regards
Stefan
