It depends.. if this is your create table statement: CREATE TABLE foo ( a smallint NOT NULL, b smallint NOT NULL, c smallint NOT NULL, d smallint NOT NULL, e smallint NOT NULL, f smallint NOT NULL, PRIMARY KEY (a,b,c,d,e,f) );
Then only one unique index is being created on the concatenate key of a+b+c+d+e+f. Queries on any fields other than A will cause a full table scan. On the other hand, if your create table is: CREATE TABLE foo ( a smallint NOT NULL, b smallint NOT NULL, c smallint NOT NULL, d smallint NOT NULL, e smallint NOT NULL, f smallint NOT NULL, PRIMARY KEY (a,b,c,d,e,f), KEY a (a), KEY b (b), KEY c (c), KEY d (d), KEY e (e), KEY f (f) ); This will create the primary key, plus six additional indexes, each of which is queryable. But in this case, the "KEY a (a)" non-unique index is redundent with the primary key, so to do what you want - a unique index on a+b+c+d+e+f PLUS the ability to independtly search the b c d e and f fields, here is the create table you'll need to use: CREATE TABLE foo ( a smallint NOT NULL, b smallint NOT NULL, c smallint NOT NULL, d smallint NOT NULL, e smallint NOT NULL, f smallint NOT NULL, PRIMARY KEY (a,b,c,d,e,f), KEY b (b), KEY c (c), KEY d (d), KEY e (e), KEY f (f) ); -- -Hank -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
