<snipped> > > Shawn, I'm not quite clear what you are saying in your second last > paragraph. When you have this situation: > > ID (autogenerated) PART_NO PART_DESCRIPTION > 1 A01 Widget > 2 B03 Grapple Grommet > 3 A02 Snow Shovel > 4 D11 Whisk > 5 C04 Duct Tape > > Do you put the PK on ID alone, PART_NO alone, or the concatentation of ID > and PART_NO? I _think_ you mean that the PK is on PART_NO alone and that ID > is simply defined unique so that it can be the target for FKs that refer to > it but I want to be sure I'm not misreading you.... > > Rhino > >
You figured me out. There would be a UNIQUE on ID and the PK on just PART_NO. With InnoDB, the PK is also a clustering index so it has the effect of storing data in PART_NO order. Since in a table like this you probably search on PART_NO quite frequently that works out just fine as an additional optimization. Shawn Green Database Administrator Unimin Corporation - Spruce Pine
