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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.

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.

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

Find an admin who will actually help!?! In this case, open a problem ticket about the poor performance and assign it to the admin.

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.

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?

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!

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?

Hi,

You do it from the Column Analysis workspace.
Please see: https://www-01.ibm.com/support/knowledg ... ml?lang=en

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

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.

I do not find any option to select the Virtual table .could you please provide details where exactly i need to select

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).