Re: How does Oracle use indexes?
From: Michael P. Stein <mstein_at_access.digex.net>
Date: 4 Oct 1993 11:31:37 -0400
Message-ID: <28pfkp$7d8_at_access.digex.net>
Date: 4 Oct 1993 11:31:37 -0400
Message-ID: <28pfkp$7d8_at_access.digex.net>
[question about "overlapping" indices (c1,c2), (c1,c2,c3), and (c1,c2,c3-c6)]
In V6, the shortest of the three indices which is UNIQUE is not redundant, as it enforces the primary key. (In V7, if the PRIMARY KEY constraint for the table is set, such an index is created automatically, and an attempt to create such an index will fail with the message that an index on the columns already exists.)
-- Mike Stein The above represents the Absolute Truth. POB 10420 Therefore it cannot possibly be the official Arlington, VA 22210 position of my employer.Received on Mon Oct 04 1993 - 16:31:37 CET