Composite Index

[rpardip]

I have the a table with colA and colB and composite Primary Key. Based on the data below, which pattern would be efficient in terms of performance. Should the PK be
(colA, colB) OR (colB, colA) ???


Pattern A
========

colA colB
1 101
1 102
2 101
2 102
3 101
3 102


Pattern B
========

colB colA
101 1
101 2
102 1
102 2
103 1
103 2



[Edited by rpardip on 01-25-2001 at 05:51 PM]

[tamilselvan]

Where is your query?

[rpardip]

Query will have both the columns in the WHERE clause with AND operator.

[gsprince]

In that case, I don't think the order matters.

But with the "index compression", depends on the cardinality of the column, it may take less or more space, if the order is changed (not sure how much impact, it has on the performance)