FW: dbimport slow
The following is an e-mail from on of my team members.
The environment is HP K200 with 4 100MHz CPUs 1Gig RAM, lots of disk.
INFORMIX Version is 7.20 UC2.
Does anyone have any comments on this ?
Thanks,
Spyro Svolos
ssvolos@ual.com
spyro@i-compute.com
847 700 4294
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From: Tsai, Peter / whq, whqka
Date: Thursday, July 17, 1997 11:26AM
Team,
I've just recently started to use dbexport and dbimport utilities to
set benchmark points so that I don't need to repeat NLS (Nightly Load System)
and TPS (Transaction Processing System) to get to a certain break point.
I want to share some information with you.
Executing dbexport is very fast. For occ1001d with one nightly load
data loaded, it just takes one or two minutes to export.
However, to import the database takes much longer, usually at least one hour.
You probably think most of the time is spent loading data, don't you?
It appears this is not true. According to what is displayed on the screen,
over 80% of the time is spent on loading the SPs (stored procedures).
In addition, the loading speed seems to exponentially decay for each procedure.
In other words, loading a procedure starts out fast, and then slows down
down, and further down.
Intuitively, it seems that the language parser for SP uses a
back-tracking algorithm
which takes exponential time. However, creating an SP is usually very fast.
So I really don't know why dbimport spends so much time on SP's.
-- Peter Tsai