Are you getting something that looks like this when you look at the structure of the “Table: wp_comments”?
`Indexes:
Keyname Type Cardinality Field
PRIMARY PRIMARY 0 comment_ID
comment_post_ID INDEX None comment_post_ID
comment_approved_date_gmt INDEX None comment_approved
comment_date_gmt
comment_date_gmt INDEX None comment_date_gmt
comment_parent INDEX None comment_parent
comment_approved INDEX None comment_approved
More than one INDEX key was created for column comment_approved
Notice how in the field column shows two instances of the field comment_approved? Unless you have have duplicate or repeated keynames (usually with _2 or _3 after the name), then everything is working as it should. You can ignore the warning completely.
