Thank you so much for that explanation, Larry! The guy who designed the table thought that "more is better" so I'm trying to pare down on an excessive number of indexes.
Karen In a message dated 10/31/2012 9:46:57 PM Central Daylight Time, [email protected] writes: > << > One more question. There's a few tables with multi-column UNIQUE indexes > (rather than a concatenated computed column). I'm assuming that these > are used only for enforcing uniqueness, and not used for actual indexing > right? Because the tables also have separate single-column indexes on the > columns and I'm wondering if they are redundent. > >> > > > The single-column index on the leading column of the UNIQUE index is, as > you suspect, redundant. UNIQUE indexes are regular indexes plus an > instruction to the engine to not accept rows that would cause duplicate > entries in > the index. > > > -- > Larry >
