How to move a table to a different filegroup?
To move a table to a different filegroup involves moving the table’s clustered index to the new filegroup. The leaf level of the clustered index actually contains the table data.
When to create secondary datafiles and filegroups?
When we create a new database, we can create secondary datafiles and filegroups. Adding secondary data files helps to improve the performance. It can be created on different disk drives or separate disk partitions that reduces IO wait and read-write latency. It is recommended to keep tables and indexes in separate filegroups.
How are data files grouped in SQL Server?
Transaction Log File s: The T-Logs files log all the transaction performed to recover the database. The Log file extension in .ldf. As I mentioned above, data files can be grouped in a filegroup. While SQL Server is being installed, it creates the Primary filegroup that has a primary data file. Secondary filegroups are user-defined.
How to re-create an index from a secondary filegroup?
In the dialog box, select Storage, and in the Storage window, click the Filegroup drop-down box, select the Secondary filegroup and click OK, as shown in the following image: Changing of the index filegroup will re-create the entire index.
If we do not have a clustered index on the table, we can create a clustered index and specifying which filegroup to use. For instance, if we want to move the UserLog table that we just moved to the HISTORY filegroup back to the PRIMARY filegroup, we could issue the following command.
Is the userlog table in the history filegroup?
We can see the UserLog table is now in the HISTORY filegroup. However, the table no longer has a clustered index. If you need a clustered index, you would need to create one for the UserLog table. If we do not have a clustered index on the table, we can create a clustered index and specifying which filegroup to use.