Database Reference
In-Depth Information
Figure 15-1.
Data layout of dbo.OrdersPT table
Each partition can reside on its own filegroup and have its own data compression method. However, all partitions
have exactly the same schema and set of indexes controlled by the
logical
table. Moreover, SQL Server does not
maintain individual statistics at the partition level. There is a single 200-step histogram on the index, regardless of
whether it is partitioned or not.
■
SQL Server 2014 can track the number of statistics column updates at the partition level and marks statistics
as outdates when it exceeds the update threshold on an individual partition. this behavior needs to be enabled with the
statistics_incremental
index and
incremental
statistics options respectively.
Note
Table partitioning can be implemented in a transparent manner to the client applications. The code continues to
reference the
logical
table while SQL Server manages the internal data layout under the hood.
■
there are still some cases when you need to reference individual partitions during the query optimization stage.
We will talk about these cases later in the chapter.
Note
