I have some basic index questions that maybe someone can help with. I
am just trying to get a better understanding of how this works (without
becoming a DBA). If I have a table with fields A, B, and C and it has
lots of records. Field A is mostly the same value, field B has a mix of
values and field C is almost unique in every record. Given that, here
are my questions:
1) Is an index that is created in the order A, B, and C better than one
created in the order C, B, and A?
2) When doing a SELECT, is the WHERE clause better being "A=x AND B=y
AND C=z" or "C=z AND B=y AND A=x", or no difference?
3) If I had an index on that table of "A,B" and an index just on field
"A", how does the system know which index to use and would having these
2 indexes actually hurt?
Thanks for any insight you can provide.
Received on Wed Sep 07 2005 - 22:36:02 CDT
