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| Arie Nugraha wrote:
> Hi list,
>
> I Have a problem with my query that fetch about 22.000 records from
> database, the query is like this :
>
> SELECT SQL_CALC_FOUND_ROWS DISTINCT b.biblio_id, b.title,
> a.author_name FROMbiblio AS b LEFT
> JOIN biblio_author AS ba ON b.biblio_id=ba.biblio_id LEFT JOIN
> mst_author AS
> a ON ba.author_id=a.author_id WHERE b.biblio_id IS NOT NULL GROUP BY
> b.biblio_id ORDER BY b.input_date DESC LIMIT 0, 10
>
> it took about 6 seconds to complete the query in localhost. I already make
> an Indexes on each table, but still the performance is slow.
> Anyone have an idea how to optimize the query so result is faster?
Why are you doing a distinct AND a group by? You don't need both, just
use the DISTINCT.
I'm guessing biblio(biblio_id) is a primary key - you don't need:
b.biblio_id IS NOT NULL
What indexes do you have? You need ones on each field in the joins:
biblio(biblio_id)
biblio_author(biblio_id, author_id)
mst_author(author_id)
--
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