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Old 06-03-04, 09:55
dsusendran dsusendran is offline
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Talking Enabling Multipage File Allocation

Db2 8.1.5 on Windows 2000 Server

I am using SMS and would like to enable multipage file allocation to increase the performance. Could anyone guide me how to do so? I was not able to find "db2empfa" command in the bin directory.

Also i would like to know what are the factors which could be altered to give a thrust in the performance of the DB. Like what configuration parameters would do increase the performance? My main concerns are bulk inserts and nested queries.

Other info:
512 MB Ram, Pentium 3, 600 MHz. <-- This is just a test machine
300 tables, Avg. of 400,000 records in some tables (most are empty), Maximum of 14,000,000 records (about 5 tables).

Thanx in advance,

Newbie
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Old 06-03-04, 10:12
sathyaram_s sathyaram_s is offline
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my aix db2 box has db2empfa ..

Stop the database and then issue
db2empfa <dbname>

The important parms are logbuffer for insert performance and sortheap for queries .. Additonal parms include - your tablespace extent and prefetch size, numioservers,numiocleaners etc.

Why not use DMS ?



Cheers
Sathyaram
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Old 06-03-04, 10:28
dsusendran dsusendran is offline
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Talking Thanks

Sathyaram,

I guess the articles i read influenced me (mind you i am a rookie).

http://www-106.ibm.com/developerwork..._adamache.html

and

http://www.dbforums.com/archive/index.php/t-887567.html

suggested that the major gains on DMS are fast disappearing.

Thanks,
Newbie
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Old 06-03-04, 10:49
sathyaram_s sathyaram_s is offline
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I don't deny that the gap is disappearing, but isn't it still there ...

Again, the advantage of using DMS over SMS may be less significant if you are using Enterprise level storge system like IBM Shark, EMC etc. These storage systems handle your IO very efficiently ...
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Old 06-03-04, 15:24
rubystep rubystep is offline
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Don't forget that if the database is using DPF (aka EEE), then one needs to issue db2_all "db2empfa db-alias" .
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