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You are right that this join query should be equivalent. However, with InnoDB there will not be much benefit from your suggested index. In InnoDB primary inde
by oysteing 11y ago
You are right that this join query should be equivalent. However, with InnoDB there will not be much benefit from your suggested index. In InnoDB primary indexes are clustered. Hence, any column may be retrieved from the B-tree of the primary index.
- deleted 11y ago[deleted]
- jfrisby 11y agoOnly if the columns are stored on-page with the index, which is not guaranteed -- it depends on what other columns exist in the table, etc.