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IA column analysis
Posted: Fri Aug 28, 2015 4:59 am
by vamsi_4a6
When we are running column analysis on a table it is taking long time(more than 3 to 4 hours)even though volume of data is less on table.Not able to figure it out the root cause and from where i have start to find the issue.
Posted: Fri Aug 28, 2015 6:26 am
by rkashyap
Is the column analysis slow for a specific table or is this true for all tables? Is the table local/remote, indexed ... how big? Also share information about your hardware.
Posted: Sat Aug 29, 2015 4:28 am
by vamsi_4a6
It is slow for all tables and how to get below information without checking with admin
Is the table local/remote, indexed ... how big? Also share information about your hardware.
My admin is not willing to share that information as per company policies
Posted: Mon Aug 31, 2015 7:27 am
by qt_ky
Find an admin who will actually help!?! In this case, open a problem ticket about the poor performance and assign it to the admin.
Posted: Mon Aug 31, 2015 11:40 pm
by ray.wurlod
Column analysis should not use any indexes; basically it issues the query SELECT * FROM tablename against the database (or just the specified columns if relevant).
Sampling is performed within Information Analyzer.
The only time indexing might be useful is a virtual table in Information Analyzer that includes a WHERE clause.
Remote tables can be expected to deliver results more slowly than local ones; this is a network issue, not an Information Analyzer issue. It would not matter which client you used.
Posted: Fri Sep 04, 2015 2:11 am
by vamsi_4a6
1)can i run column analysis by submitting a sql query because i want to restrict the data before running column analysis?If not how to fetch limited data without using sample technique?
Posted: Fri Sep 04, 2015 7:42 am
by rjdickson
Hi,
You can create a virtual table that applies a 'where' clause to reduce the rows/columns being used. You would then use that virtual table as input to your column analysis.
I hope this helps!
Posted: Fri Sep 04, 2015 8:37 am
by vamsi_4a6
I found the option in IA for virtual column but i did not find any option related for virtual table.where exactly it is present?
Posted: Fri Sep 04, 2015 8:40 am
by rjdickson
Hi,
You do it from the Column Analysis workspace.
Please see:
https://www-01.ibm.com/support/knowledg ... ml?lang=en
Posted: Fri Sep 04, 2015 8:51 am
by vamsi_4a6
Thanks alot for input.How to give this virtual table as input while running columns analysis for a particular table.because i can see only Run now,sample ands chedule options
Posted: Fri Sep 04, 2015 7:18 pm
by qt_ky
From the Column Analysis workspace, select the virtual table you created, then click on the Run Column Analysis task. Selecting Run Now is fine, then click Submit.
Posted: Fri Sep 04, 2015 10:47 pm
by vamsi_4a6
I do not find any option to select the Virtual table .could you please provide details where exactly i need to select
Posted: Fri Sep 04, 2015 11:12 pm
by ray.wurlod
You have to "create" the virtual table definition first - by specifying the columns and WHERE clause and giving it a name. Once you have saved this it will appear in the list of tables available for running Column Analysis (and, later, the other analyses).