RE: Informatica Bulk Mode behavior

  • From: "Thomas Jeff" <jeff.thomas@xxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 26 Apr 2004 07:48:28 -0500

Waleed, =20

Indeed you were on the right track.   We got the following msg from
Informatica
Support.   "Oracle design limitation"??????    =20


Problem:

In 6.x version running session targeting to Oracle using bulk mode
creates new extents=20
at every commit. This sometimes leads to the following error: "ORA-01568
unable to create=20
initial extent."=20

Solution:

This is a known issue (CR 53791) that occurs when using Oracle bulk
loading. To resolve this=20
issue increase the commit interval to very high value. SUPPORTING
INFORMATION: This issue is=20
due to the following design limitation in Oracle: Direct Path Loading
(using same code as bulk=20
loading) is going to use only blocks above the high water mark. Also
Direct Path loading does=20
not check for Partial blocks are not used, so no reads are needed to
find them and fewer writes=20
are performed. In a conventional data load the bind array buffer is
filled and passed to Oracle=20
with a SQL INSERT command which results in the space management by the
SQL Command Processing to=20
be utilized. Therefore bulk loading will allocate more extents.=20


-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Khedr, Waleed
Sent: Thursday, April 22, 2004 11:34 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: Informatica Bulk Mode behavior


I would ask the developers how they configured the commit interval (if =
=3D
it's set to a very low value)

Waleed

-----Original Message-----
From: Thomas Jeff [mailto:jeff.thomas@xxxxxxxxxxx]
Sent: Thursday, April 22, 2004 10:33 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: Informatica Bulk Mode behavior


List,
Is anyone familiar with how Informatica's bulk mode works?  =3D20

We have a situation where I created a 4GB tablespace for a new and
simple=3D20 truncate/load operation from Informatica, around 7 million
rows estimated=3D20 to take up 1.5GB. =3D20  =3D20 Using bulk mode, =
which
appears to be a direct load (in the SQL cache, the=3D20 INSERT statement
has a hint that I've never seen before:  SYS_DL_CURSOR which=3D20 I =
assume
stands for Direct Load), they run out of space in the tablespace
after=3D20 about 200K rows have been inserted.

If I then manually rebuild the table, the 200K rows gets compressed back
down=3D20 to one extent.

So there's a lot of either empty or preallocated space.    Thinking
somehow=3D20
the high-water mark was the culprit, I manually truncated the table
before=3D20 they reran their job.  =3D20

Still the same problem.  =3D20

If the job runs in 'normal' mode, which is row-by-row processing, it
runs fine,=3D20 although of course, performance is quite poor.

Any ideas/experience as to how this bulk mode operates?

Thanks.


--------------------------------------------
Jeffery D Thomas
DBA
Thomson Information Services
Thomson, Inc.

Email: jeff.thomas@xxxxxxxxxxx

Indy DBA Master Documentation available at: http://gkmqp.tce.com/tis_dba
--------------------------------------------



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