This is documented at https://sqlite.org/eqp.html#the_explain_query_plan_command, complete with the caveat that it is for interactive debugging only and subject to change without notice. Some releases would output the estimated number of rows, and the virtual table interface requires the implementation to return it.
-----Ursprüngliche Nachricht----- Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im Auftrag von Dominique Devienne Gesendet: Montag, 18. September 2017 10:45 An: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> Betreff: Re: [sqlite] [EXTERNAL] Number of rows in answer set On Mon, Sep 18, 2017 at 10:37 AM, Hick Gunter <h...@scigames.at> wrote: > SQLite uses some nifty heuristics to estimate the number of rows it > expects to process while formulating a query plan. [...] > Is there any way to get at that estimate? That would be interesting to pre-size some result buffers ahead of time to avoid reallocs. Even with all the usual disclaimer and caveats that it's just an estimate if would be very useful IMHO. Could we have an API for that? --DD _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users ___________________________________________ Gunter Hick Software Engineer Scientific Games International GmbH FN 157284 a, HG Wien Klitschgasse 2-4, A-1130 Vienna, Austria Tel: +43 1 80100 0 E-Mail: h...@scigames.at This communication (including any attachments) is intended for the use of the intended recipient(s) only and may contain information that is confidential, privileged or legally protected. Any unauthorized use or dissemination of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by return e-mail message and delete all copies of the original communication. Thank you for your cooperation. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
