Hi, >> The database can't use the index on the order by column if it is >> already using another index to speed up the join. Basically, the >> database can only use one of the indexes, not two at a time. > > I beg to disagree. In case of > > SELECT * FROM details JOIN master ON master.filepath = > details.filepath > ORDER BY details.action > LIMIT 10; > > the details may be read using idx_action and the corresponding rows > from master may be found using its PK. IMHO, this should work, since > it reduces the work considerably. I'm quite sure it works with MySql.
OK I change my sentence to: "The database can't use the index on the order by column if it is already using another index *on the same logical table* to speed up the join." Regards, Thomas -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/h2-database?hl=en.
