While reading planstats.sgml, I encounted a sentence which I don't understand.
These numbers are current as of the last <command>VACUUM</> or <command>ANALYZE</> on the table. The planner then fetches the actual current number of pages in the table (this is a cheap operation, not requiring a table scan). If that is different from <structfield>relpages</structfield> then <structfield>reltuples</structfield> is scaled accordingly to arrive at a current number-of-rows estimate. In this case the value of <structfield>relpages</structfield> is up-to-date so the rows estimate is the same as <structfield>reltuples</structfield>. I don't understand the last sentence (In this case...). For me it seems it is talking about the case when replages is not different from what the planner fetches from the table. If so, why "In this case"? Isn't "In this case" referrers to the previous sentence (If that is different from...)? Maybe "In this case" should be "Otherwise" or some such? Best regards, -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese:http://www.sraoss.co.jp -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers