Re: Huge performance drop when using prepared statement

On 08/12/2007, Martin Jenkins <[email protected]> wrote:
> Markus Gritsch wrote:
>  > Hi,
>  >
>  > when using bind variables I get a huge performace drop compared to
>  > using a plain string.  The query is demonstrated in the attached file
>  > "problematic_query.py".
>
> I don't claim to understand the output, but the EXPLAIN command shows
> that the two queries are completely different. The slow query has one
> statement which mentions KeyInfo and the fast query has two. It seems
> reasonable to assume that KeyInfo ==> index so the difference is that
> SQLite (or its query parser) can't use both indexes for the statement
> with the bound variable. I suggest you post this on the actual SQLite
> mailing list and see what DR Hipp says; it might be a bug or feature.
>
> Apologies for replying to this offlist. I can't post to the list from
> the address that I'm subscribed with at the moment.
>
> Martin

Thank you, I will post it on the sqlite list.