RE: Informatica Bulk Mode behavior

  • From: "Mohan, Ross" <RMohan@xxxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 22 Apr 2004 16:28:51 -0400

Whereas with regular indexes they don't take space?  ;-)
Believe if you have, as one example, a FULLY packed, fresh
index on tab(col) with pctfree 0 and defaulted freelisting
and add a few thousand rows via APPEND you are going to get 
the same resultant index size if you added the rows via 
conventional means. 


...your experiences may well be different, but....just a wayt
of saying that mostly the pctfree of the idx and its freelists 
config will drive a lot of the space (mis?)usage. 

HTH



-----Original Message-----
From: Rajesh.Rao@xxxxxxxxxxxx [mailto:Rajesh.Rao@xxxxxxxxxxxx] 
Sent: Thursday, April 22, 2004 2:34 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: Informatica Bulk Mode behavior



One thing of note that I have encountered with Direct Load Inserts is that
the Indexes on the table will require twice the space. Say, you have indexes
of size 2 Gb, then after the direct insert, the exisiting index is merged
onto a "temporary" segment along with the new index keys.  So, check if you
are running out of space coz of the indexes.

Regards
Raj



 

                    "Khedr, Waleed"

                    <Waleed.Khedr@xxxxx       To:
<oracle-l@xxxxxxxxxxxxx>                                          
                    OM>                       cc:

                    Sent by:                  Subject:     RE: Informatica
Bulk Mode behavior                           
                    oracle-l-bounce@fre

                    elists.org

 

 

                    04/22/2004 01:22 PM

                    Please respond to

                    oracle-l

 

 





Multithread is a way Informatica can parallelism the load into the = target
using many concurrent sessions. Since it's direct load, each session will
try to allocate its own = extents to load into.

I would check if they have a very high number of threads.

But also since you said the job failed and the table was loaded with = some
rows (200K), this indicates that they have low setting for the = commit
interval otherwise the table will be empty.

Commit interval should be very high 1 million or higher.

Waleed

-----Original Message-----
From: Thomas Jeff [mailto:jeff.thomas@xxxxxxxxxxx]
Sent: Thursday, April 22, 2004 12:23 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: Informatica Bulk Mode behavior


Waleed,

The tablespace is locally-managed, 128MB extents.     I'll have to ask
about the multithread, can you
tell me the ramifications of it?

Thanks.


-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Khedr, Waleed
Sent: Thursday, April 22, 2004 10:24 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: Informatica Bulk Mode behavior


I use it. It's using direct load OCI.
Never had your problem.

What is the extent size (initial/next ) for the table? Are they using = =3D
=3D3D multithread in the mapping?

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?  =3D3D20

We have a situation where I created a 4GB tablespace for a new and
simple=3D3D20 truncate/load operation from Informatica, around 7 million
rows estimated=3D3D20 to take up 1.5GB. =3D3D20  =3D3D20 Using bulk = mode,
=3D which appears to be a direct load (in the SQL cache, the=3D3D20 INSERT =
statement has a hint that I've never seen before:  SYS_DL_CURSOR
which=3D3D20 I = =3D assume stands for Direct Load), they run out of space
in the tablespace after=3D3D20 about 200K rows have been inserted.

If I then manually rebuild the table, the 200K rows gets compressed back
down=3D3D20 to one extent.

So there's a lot of either empty or preallocated space.    Thinking
somehow=3D3D20
the high-water mark was the culprit, I manually truncated the table
before=3D3D20 they reran their job.  =3D3D20

Still the same problem.  =3D3D20

If the job runs in 'normal' mode, which is row-by-row processing, it runs
fine,=3D3D20 although of course, performance is quite poor.

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

Thanks.


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