This makes sense. Though, I think the documentation should cover this.
Thanks for your response. > From: paiva...@gmail.com > Date: Mon, 5 Oct 2009 09:31:10 -0400 > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] "Stored procedures" performance issue > > > IS_MY_BIRTHDAY returns 1 when the date is my birthday. Now, inside this > > function, if I encounter a date greater than my birthday, then I want to > > tell SQLite to stop searching, since the date is indexed. > > > > Is this possible? If so, how? > > Even if this was possible it would be useless because you cannot say > if SQLite traverses table via index or makes just full table scan. And > in your particular case SQLite will see that there's no benefit in > using any index and will just scan the whole table. > The general advice in this case is to add column to the table which > will store the result of your function, create an index on that > additional column and then use that column in the query. In this case > SQLite will understand that it's better to use index and will use it. > > Pavel > > On Mon, Oct 5, 2009 at 9:24 AM, Kristoffer Danielsson > <kristoffer.daniels...@live.se> wrote: > > > > When I create my own "stored procedures" using sqlite3_create_function, I > > get horrible performance (which I expected) even though the column of > > interest is INDEXED. > > > > > > Consider this sample (it's stupid, but it shows my problem): > > > > SELECT * FROM MyTable WHERE IS_MY_BIRTHDAY(IndexedDate); > > > > > > > > IS_MY_BIRTHDAY returns 1 when the date is my birthday. Now, inside this > > function, if I encounter a date greater than my birthday, then I want to > > tell SQLite to stop searching, since the date is indexed. > > > > > > > > Is this possible? If so, how? > > > > > > Thanks. > > > > _________________________________________________________________ > > Windows Live: Dina vänner får dina uppdateringar från Flickr, Yelp och Digg > > när de skickar e-post till dig. > > http://www.microsoft.com/windows/windowslive/see-it-in-action/social-network-basics.aspx?ocid=PID23461::T:WLMTAGL:ON:WL:sv-se:SI_SB_3:092010 > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _________________________________________________________________ Windows Live: Dina vänner får dina uppdateringar från Flickr, Yelp och Digg när de skickar e-post till dig. http://www.microsoft.com/windows/windowslive/see-it-in-action/social-network-basics.aspx?ocid=PID23461::T:WLMTAGL:ON:WL:sv-se:SI_SB_3:092010 _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
