Re: [HACKERS] ANALYZE command progress checker

On Tue, Mar 21, 2017 at 3:41 PM, vinayak <Pokale_Vinayak_q3@lab.ntt.co.jp> wrote:

Thank you for testing the patch on Windows platform.

Thanks for the updated patch.

It works good for a normal relation.  But for a relation that contains child tables,

the PROGRESS_ANALYZE_NUM_ROWS_SAMPLED produces wrong results.

Thank you for reviewing the patch.
The attached patch implements a way to report sample rows count from acquire_sample_rows() even if called for child tables.

How about adding another phase called PROGRESS_ANALYZE_PHASE_COLLECT_INHERIT_SAMPLE_ROWS

and set this phase only when it is an inheritance analyze operation. And adding

some explanation of ROWS_SAMPLED phase about inheritance tables

how these sampled rows are calculated will provide good analyze progress of

relation that contains child relations also.

I have added the phase called PROGRESS_ANALYZE_PHASE_COLLECT_INH_SAMPLE_ROWS.
I have also updated the documentation.

The ANALYZE command takes long time in computing statistics phase.So I think we can add some column or phase so that user can easily understand the progress.
How about adding new column like "num_rows_processed" will compute the statistics of specified column?
How about separate the computing "inheritance statistics" phase from the computing regular "single table" statistics.
Comment?

Regards,
Vinayak Pokale
NTT Open Source Software Center