Hello.
> So in this case MySQL will choose to use the largest index that suits
MySQL will choose index which returns less rows.
> Given the high cardinality of `manufacturer`
Cardinality - the number of unique values in the index. So manufacturer
index usually has low cardinality and k
Gleb Paharenko wrote:
Hello.
If you have a separate indexes on section and status columns, MySQL
will use only one of them. And as the column status has very small number
of possible values the cardinality of separate index on it will be too low
and optimizer won't use this index. I think, if slow
Hello.
If you have a separate indexes on section and status columns, MySQL
will use only one of them. And as the column status has very small number
of possible values the cardinality of separate index on it will be too low
and optimizer won't use this index. I think, if slow updates won't be
Hiya,
I've been trying to find out about this for a few days, but can't seam
to find much information about it on the web.
At the moment I've got a few tables, one of this looks like:
CREATE TABLE `news` (
`section` TINYINT UNSIGNED ZEROFILL NOT NULL,
`article` SMALLINT(4) NOT NULL AUTO_INCRE
