Re: contrib/pg_stat_statements 1202

Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Please split this into two separate patches that can be separately
> evaluated.

Sure. I want to disucuss only where to add counters of buffer usage
and cpu usage, or they should not be added. However, it seems to
affect future of EXPLAIN ANALYZE, so we might also need to discuss
about EXPLAIN.

I assume we have 3 choices here:

1. Add those counters to struct Instrument.   We can get statistics for each line in EXPLAIN ANALYZE,   but it might
haveoverhead to update counters.
 

2. Add those counters only to top instruments (one per query).   We can get accumulated statistics for each query.   It
mightbe unsufficient for complex queries.
 

3. Should not add any counters.   No changes to core, but usability of pg_stat_statement module   would be very
poor...

Which should we take? or are there another idea?

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center