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Performance

Posted: Wed Jan 11, 2012 9:42 pm
by krisna
Hi,

We are loading data from a sequential file to oracle and volume is 650 millions of records. It took 45 hours to load 318 million records, performance wise it's very poor. Job design is like this

Code: Select all

sequential file --> transformer --> oracle enterprise stage
                               |
                               V
                          oracle enterprise stage
in transformer we are using a transformation rule to check for spaces(4 columns) move to one oracle enterprise stage other move to another oracle stage.

we are using oracle load options as direct = false, parallel = true.

in oracle enterprise stage

write method = load
write mode = append

Please help us to improve performance.

Thanks in advance.

Re: Performance

Posted: Wed Jan 11, 2012 10:16 pm
by SURA
Again this is relates to performance.

Did you made any changes in Number Of readers per node ?

All the records are in the same file / set of files?

Find a way to split the data and load one after another.

DS User

Posted: Wed Jan 11, 2012 10:52 pm
by vmcburney
There are several things that could slow your job down. 1) make sure there is no sorting going on as this is a huge overhead. 2) Make sure you are reading from the sequential file with multiple reads so you do not have a sequential bottleneck. 3) From memory the version 7 Oracle Enterprise stage first has to create an Oracle bulk load file and then call the bulk load command. Sometimes it is faster to create the bulk load file using the Sequential file stage and to call Oracle bulk load after the file is ready.

Does anyone remember whether the version 7 Oracle Enterprise stage is slow to build the bulk load file?

Posted: Wed Jan 11, 2012 10:55 pm
by chulett
I seem to recall it pushing data through a named pipe. :?

Curious why "direct=false"? At that point you've got a conventional load rather than a bulk load... indexes?

Posted: Wed Jan 11, 2012 11:41 pm
by chandra.shekhar@tcs.com
You can also use Oracle Connector stage as your target since it also works in parallel mode.

Posted: Thu Jan 12, 2012 12:25 am
by chulett
... if only it was in the 7.x release. :(

Posted: Thu Jan 12, 2012 5:55 am
by nagarjuna
Do you have indexes on the target table ? Check the possibility of loading in direct load ..

Posted: Thu Jan 12, 2012 8:53 am
by krisna
It's not a fixed width file. We are using version 7. We have indexes on tables.