SQL dotaz
Tom Meinlschmidt
hw na meinlschmidt.org
Pondělí Listopad 14 15:25:33 CET 2016
Ahoj,
a indexy nad tema tabulkama mas?
ukaz vysledek
explain select * from meta3 where… order by …
tm
> On Nov 14, 2016, at 15:21 , Kosťa MK <kosta na cti.si> wrote:
>
> Zdravím,
>
> mám následující problém:
>
> Nad databází mám vytvořen relativně složitý view:
>
> CREATE VIEW meta3 AS SELECT id,
> title,
> (SELECT author_sort FROM authors WHERE authors.id IN (SELECT author from books_authors_link WHERE book=books.id)) authors,
> (SELECT name FROM series WHERE series.id IN (SELECT series FROM books_series_link WHERE book=books.id)) series,
> series_index,
> (SELECT group_concat(name) FROM tags WHERE tags.id IN (SELECT tag from books_tags_link WHERE book=books.id)) tags,
> (SELECT group_concat(value) FROM custom_column_1 WHERE custom_column_1.id IN (SELECT value from books_custom_column_1_link WHERE book=books.id)) genre,
>
> (SELECT group_concat(value) FROM custom_column_2 WHERE custom_column_2.id IN (SELECT value from books_custom_column_2_link WHERE book=books.id)) type,
> path,
> (SELECT name FROM data WHERE data.book=books.id) file,
> (SELECT group_concat(format) FROM data WHERE data.book=books.id) formats,
> timestamp
> FROM books
>
> funguje perfektně, jenže je zoufale pomalý pokud se pokusí o ORDER nad libovolným sloupcem
>
> Mohl by mě pridím někdo nakopnout jak to zrychlit?
>
> S pozdravem
> Kosta
>
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--
===============================================================================
Tomas Meinlschmidt, MS {MCT, MCP+I, MCSE, AER}, NetApp Filer/NetCache
www.meinlschmidt.com www.maxwellrender.cz
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