> From: Tom Lane [mailto:t...@sss.pgh.pa.us]
> "Etsuro Fujita" <fujita.ets...@lab.ntt.co.jp> writes: > > ISTM it would be better to update the text about index cost estimation in > > indexam.sgml. Please find attached a patch. > > I'm not too thrilled with the proposed patch. In the first place, I > don't think it's necessary to address costing of index order-by > expressions in an introductory explanation. Agreed. > In the second, this change > makes the code less clear, not more so, because it introduces a variable > indexQuals without showing where you would get that value from. Agreed. However, I am concerned about the next comment in the current code: /* * Our generic assumption is that the index pages will be read * sequentially, so they cost seq_page_cost each, not random_page_cost. * ... I think this assumption is completely wrong, which has given me a motivation to propose a patch, though I am missing something. Thanks, Best regards, Etsuro Fujita -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
