Nicole is working on migrating on-premises SQL Server databases to Azure SQL data warehouse(Synapse dedicated SQL pools) tables.
The tables of the dedicated SQL pools of Synapse Analytics require partition.
She's designing SQL table partitions for this data migration to the Azure Synapse.
The partition of the tables already contains the data, and she's looking for the most efficient method to split the partitions in the dedicated SQL pool tables.
What T-SQL statement can she use for splitting partitions that contain data?
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A. B. C. D.Correct Answer: A.
To split partitions in Azure Synapse dedicated SQL pools tables, the most efficient method to use is the ALTER TABLE SWITCH statement.
The ALTER TABLE SWITCH statement is a T-SQL statement that allows for the efficient and fast movement of data between two tables. It is specifically designed for splitting, merging or moving partitions between two tables.
When using ALTER TABLE SWITCH, the two tables involved in the process must have the same schema and partition function. This means that both tables must have the same number of columns and data types. The partition function is a way of defining how data is partitioned in a table based on a specific column or set of columns.
To split a partition that already contains data, the following steps can be taken using ALTER TABLE SWITCH:
For example, suppose we have a table named Sales with a partition function based on the SalesDate column. If we want to split the partition for the year 2022, we can follow the steps below:
Create a new empty table named Sales2022_new:
CREATE TABLE Sales2022_new ( SalesID int, SalesDate date, ProductID int, Qty int ) WITH ( DISTRIBUTION = HASH(ProductID), CLUSTERED COLUMNSTORE INDEX ) ;
Use the ALTER PARTITION FUNCTION statement to split the partition:
ALTER PARTITION FUNCTION SalesPF() SPLIT RANGE ('20220101');
Use the ALTER TABLE SWITCH statement to move the data from the original table to the new table:
ALTER TABLE Sales SWITCH PARTITION 4 TO Sales2022_new;
In this example, partition 4 contains data for the year 2022, and the ALTER TABLE SWITCH statement moves this data from the original table to the new table. Once the data has been moved, the original partition can be dropped.
In conclusion, to split partitions in Azure Synapse dedicated SQL pools tables that already contain data, the ALTER TABLE SWITCH statement is the most efficient method to use.