SQL Server data table partition optimization database

Are you struggling to optimize your SQL Server database? If your database contains many very large tables, the partition function can help you a lot, because it can split these large tables into independent file groups. This technology allows you to distribute data across different physical disks and optimize your query performance by adjusting their parallelism.

The SQL Server data table partition process is divided into three steps:

1) create a partition function

2) create a partition scheme

3) partition the table

Partition Function DefinitionHowThat is, you want SQL Server to partition data. Here, we will not use a table as an example, but summarize the technology of data segmentation.

Partitions are implemented by specifying the dividing line of each partition. For example, assume that we have a mers MERs table that contains information about all the Customers of the enterprise. The customer information is identified by a unique customer number, ranging from 1 to 1000000. We can use the following Partition Function (customer_Partfunc) to divide the table into four partitions equally:

Create partition function customer_partfunc (int)

AS RANGE RIGHT

For values (750000)

The split boundary specifies four partitions. The first partition contains all records whose values are less than 250000. The second partition contains all records with values between 250000 and 499999. The third partition contains all records with values between 500000 and 749999. All other records greater than or equal to 750000 are included in the Fourth partition.

Note that the "range right" clause is used in this example. This indicates that the demarcation value is on the right side of the partition. Similarly, if the range left clause is used, the first partition contains all records whose values are less than or equal to 250000; the second partition will contain all records with values between 250001 and 500000, and so on.

Once you have created a partition function that defines how to partition data, the next step is to create a partition scheme, defineWhereThat is, where you want to partition the data. This is a straightforward process. For example, if I have four file groups named from "fg1" to "fg4", the following partition scheme can be used:

Create partition scheme customer_partscheme

As partition customer_partfunc

TO (fg1, fg2, fg3, fg4)

Note that we have connected a partition function to the partitioning scheme, but we have not connected the partitioning scheme to any specific database table. This is the time to reuse the function. We can use this function to apply the Partition Scheme (or just a partition function) to any data in the database table.

After creating the partition scheme, you can partition the table. This is the simplest step. You only need to add the "ON" clause in the table creation statement to specify the table partitioning scheme and the table columns to apply the partitioning scheme. You do not need to specify the partition function, because the partition function has been defined in the Partition Scheme.

For example, if you want to use the preceding partitioning scheme to create a customer table, you need to use the following Transact-SQL statement:

Create table MERs (FirstNamenvarchar (40), LastNamenvarchar (40), CustomerNumberint)

ON customer_partscheme (CustomerNumber)