JtheRipper
IS-IT--Management
Hi there,
I would like to know whether my understanding of the clustered index is correct or not.
We are having performance problems on a 50GB SQL Server 2000 database, and I am running out of ideas.
I checked the 3 bigest tables on the database, approx 10 - 30 million rows, and none of them have a clustered index. They do have quite a number (too many in my opinion for an OLTP system) of non-clustered indexes.
Am I correct in saying that it is ALWAYS a good idea to have a clustered index on a table, especially big tables such as these?
BOL also states:"CLUSTERED - Creates an object where the physical order of rows is the same as the indexed order of the rows, and the bottom (leaf) level of the clustered index contains the actual data rows"
Does this mean that the table will be recreated? I was always under the impression that by creating a clustered index you will create an index with i.e. 3 columns and only those columns' data will be the actual rows and not pointers like in non-clustered index. But after reading the BOL description a few times it looks like the table will be reorganized to "match" the index...
Any input/comments to help clear up my confusion will be greatly appreciated!
Thanks,
J.
I would like to know whether my understanding of the clustered index is correct or not.
We are having performance problems on a 50GB SQL Server 2000 database, and I am running out of ideas.
I checked the 3 bigest tables on the database, approx 10 - 30 million rows, and none of them have a clustered index. They do have quite a number (too many in my opinion for an OLTP system) of non-clustered indexes.
Am I correct in saying that it is ALWAYS a good idea to have a clustered index on a table, especially big tables such as these?
BOL also states:"CLUSTERED - Creates an object where the physical order of rows is the same as the indexed order of the rows, and the bottom (leaf) level of the clustered index contains the actual data rows"
Does this mean that the table will be recreated? I was always under the impression that by creating a clustered index you will create an index with i.e. 3 columns and only those columns' data will be the actual rows and not pointers like in non-clustered index. But after reading the BOL description a few times it looks like the table will be reorganized to "match" the index...
Any input/comments to help clear up my confusion will be greatly appreciated!
Thanks,
J.