RE: DDL vs. DDS performance

["Elvis Budimlic" <ebudimlic@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Dmitri

Way I understood Dan's article (perhaps erroneously) is that he was focusing
on the time it takes to bring the file from DASD to main storage, see
sentence: "The process of bringing data from auxiliary storage to main
memory is significantly improved when the file has been created using SQL
DDL.".  

I believe key factor in his tests are that he is purging the file out of
main memory between each run, see line: "I ran the test several times,
purging the database objects from memory before each run."

In your testing, do you purge the objects out of memory between the runs?  
I think the best way to accomplish this is via SETOBJACC POOL(*PURGE) or
alternatively CLRPOOL commands.
If you're not purging the files out of main memory, I can see where your
test results would differ from Dan's.  

I'm curious to see your hard numbers on the difference between dds and ddl
you see when files are memory resident.

Elvis
 
-----Original Message-----
Subject: DDL vs. DDS performance


Another point:

do somebody able to confirm the performance boost of SQL created tables?

I repeated what was written in the article
(http://www.iseriesnetwork.com/resources/artarchive/index.cfm?fuseaction=vie
warticle&CO_ContentID=20067&channel=) and made about 50 tests more with no
success (program run nearly the same time reading DDS o SQL created file).

Dmitri Efimov