To enhance read performance and reduce disk usage, TiDB automatically schedules data compaction on storage nodes in the background. During the compaction, storage nodes rewrite physical data, ...

When you alter the attributes of a column and an index has been defined for that column, the values in the altered column continue to have the index defined for them. If you drop a column with the ...

You can modify or drop a check constraint in SQL using the ALTER TABLE statement. To modify a check constraint, you need to drop the existing one and create a new one with the updated condition.

ALTER TABLE EMPLOYEE ADD CONSTRAINT REVENUE CHECK (SALARY + COMM > 30000) Example 5: Alter table EMPLOYEE. Drop the constraint REVENUE which was previously defined. ALTER TABLE EMPLOYEE DROP ...

For more information on the new SQL Server 2014 syntax for using managed lock priority and single partition online index rebuild, see the ALTER TABLE (Transact-SQL) and ALTER INDEX (Transact-SQL) ...

Truncate statement syntax is: TRUNCATE TABLE table_name; For example: TRUNCATE TABLE Employee; In this example, we’re marking all the extents of the Employee table for deallocation, so they’re ...

The first form of the CREATE TABLE statement creates tables that automatically map SQL data types to those supported by the SAS System. ... To modify integrity constraints, use the ALTER TABLE ...

SQL Reference. ALTER TABLESPACE. The ALTER TABLESPACE statement is used to modify an existing table space in the following ways. Add a container to a DMS table space (that is, one created with the ...