Tino Wildenhain wrote:
Thomas Vatter schrieb:
Tino Wildenhain wrote:
Thomas Vatter schrieb:
is there a possibility for creating views or temp tables in memory
to avoid disk io when user makes select operations?
No need. The data will be available in OS and database caches if
they are really required often. If not, tune up the caches and
do a regular "pre select".
Regards
Tino
hmm, I am selecting a resultset with 1300 rows joined from 12 tables.
with jdbc I am waiting 40 seconds until the first row appears. The
following rows appear really fast but the 40 seconds are a problem.
Well you will need the equally 40 seconds to fill your hypothetical
in memory table. (even a bit more due to the creation of a
datastructure).
So you can do the aproaches of semi materialized views (that are in fact
writing into a shadow table) or just prefetch your data at time - just
at the times you would refill your memory tables if they existed.
A cronjob with select/fetch should do.
Regards
Tino
If the in memory table is created a bootup time of the dbms it is
already present when user selects the data. Of course the challenge is
to keep the in memory table up to date if data are changed. What do you
mean with semi materialized views, I have tried select * from this_view
with the same result. Also, if I repeat the query it does not run faster.
regards
tom
--
Mit freundlichen Grüßen / Regards
Vatter
Network Inventory Software
Sun Microsystems Principal Partner
www.network-inventory.de
Tel. 030-79782510
E-Mail thomas.vatter@xxxxxxxxxxxxxxxxxxxx
