Hi Gail,

The article was very helpful. I wasn't aware that the order of the columns in the index mattered, but now I understand why.

So, my conclusion from that is, the advantage of having 10 indexes on a single column is that a larger number of queries will find an index it can use. The disadvantage being it will have to do checks against the index seek results for each other column filter in the query.

The advantage of 5 indexes with 4 columns each(the first column being different for each index) is that some queries (using all or some of the columns in index order) can find all the results in a single seek. The disadvantage is that now, for a query to use one of the 5 indexes, it must be referencing one of the 5 first columns, otherwise it cannot use any of the indexes.

Am accurate in saying that?

Also, there is another aspect of this issue we haven't talked about yet: Is there any difference in the maintenance of the two index structures? Will reindexing 10 indexes with single columns take longer than fewer indexes with more columns? Which index structure will slow down inserts more?

Any insight to this side of the issue would be appreciated too.

Thanks,

Nathan