At the end of the operation, autostats that reference the column are dropped and user-created stats are invalidated. You can run REBUILD as an ONLINE operation. If the table isn't in the current database or contained by the schema owned by the current user, you must explicitly specify the database and schema. ALTER TABLE permissions apply to both tables involved in an ALTER TABLE SWITCH statement. Although the columns and column names must be the same, the partition boundaries don't need to be the same. In Microsoft SQL Server 2012 Enterprise and higher, the number of processors employed to run a single ALTER TABLE ADD (index-based) CONSTRAINT or DROP (clustered index) CONSTRAINT statement is determined by the max degree of parallelism configuration option and the current workload. For more information, see Temporal Tables and Getting Started with Temporal Tables in Azure SQL Database. The following query returns the name of the partitioning column for table. No additional syntax is required to implement the online operation beyond the ADD COLUMN syntax.

For more information, see Configure the max degree of parallelism Server Configuration Option. Use the REBUILD PARTITION syntax to rebuild a single partition in a partitioned table. WAIT_AT_LOW_PRIORITY indicates that the online index rebuild operation waits for low-priority locks, allowing other operations to carry on while the online index build operation is waiting. ALTER TABLE table_name ADD column_name_1 data_type_1 column_constraint_1, column_name_2 data_type_2 column_constraint_2,..., column_name_n data_type_n column_constraint_n; In this syntax, you specify a comma-separated list of columns that you want to add to a table after the ADD clause. Specifies that trigger_name is enabled or disabled. When you delete a constraint that created a clustered index, the data rows that were stored in the leaf level of the clustered index are stored in a nonclustered table. Specifies the data compression option for the specified table, partition number, or range of partitions.

If not specified, the column is assigned the default collation of the database. DEFAULT, PRIMARY KEY, and UNIQUE constraints can't be disabled. The following example deletes a PRIMARY KEY constraint with the ONLINE option set to ON. The following example adds a column that allows null values and has no values provided through a DEFAULT definition. When executing, the SWITCH or rebuild operation prevents new transactions from starting and might significantly affect the workload throughput and temporarily delay access to the underlying table. If the new column allows null values and you add a default definition with the new column, you can use WITH VALUES to store the default value in the new column for each existing row in the table. The following examples A through C use the FactResellerSales table in the AdventureWorksPDW2012 database. ADD } The ALTER TABLE

REBUILD WITH ... syntax rebuilds all partitions. Reassigns all data in one partition of a partitioned table to an existing non-partitioned table. The scale for the specified data type. For details, see Always Encrypted with secure enclaves. ALTER column isn't run as online regardless of which value was specified for ONLINE option. In other words, escalation will be allowed to the partition level. Parallel index operations aren't available in every edition of SQL Server. Copyright © 2003-2020 The new constraint is evaluated in all later data updates. For memory-optimized tables, you can add an index.

Although the duration of the lock for online index rebuild is short, waiting for all open transactions on a given table to complete and blocking the new transactions to start, might significantly affect the throughput. The following example creates the PRIMARY KEY constraint PK_TransactionHistoryArchive_TransactionID and sets the options FILLFACTOR, ONLINE, and PAD_INDEX. Switches a partition from one partitioned table to another. While using this site, you agree to have read and accepted our Terms of Service and Privacy Policy. { ENABLE | DISABLE } CHANGE_TRACKING Specifies the name of the trigger to disable or enable. The data of PARTITION 2 of table PartitionTable is then switched into table NonPartitionTable. You can change the length, precision, or scale of a column by specifying a new size for the column data type. For more information about valid scale values, see Precision, Scale, and Length. The first example removes a UNIQUE constraint from a table. ALTER TABLE with the SET FILESTREAM_ON clause succeeds only if the table has no FILESTREAM columns. You can drop the clustered index and move the resulting table to another filegroup or partition scheme in a single transaction by specifying the MOVE TO option. SET ( SYSTEM_VERSIONING = { OFF | ON [ ( HISTORY_TABLE = schema_name . Multiple columns can be listed. The following example adds a new column with a UNIQUE constraint. After the lock is escalated to the HoBT level, the lock will not be escalated later to TABLE granularity. For more information, see Enable Stretch Database for a table and Select rows to migrate by using a filter function - Stretch Database. Optionally, you might also want to drop the period columns used by the system to record system versioning information. This SQL Server ALTER TABLE example will add a column to the employees table called last_name. If the table isn't partitioned, the lock escalation is done to the TABLE granularity. Next, column 'C2' is encrypted with a column encryption key, named CEK1, and randomized encryption. Adding or removing triggers on base tables isn't affected by creating a schema-bound view that references the tables. ALL For additional assistance, see Getting Started with System-Versioned Temporal Tables. type_name can be any one of the following types: The following are criteria for type_name of an altered column: If the COLLATE clause isn't specified, changing the data type of a column causes a collation change to the default collation of the database. After you disable Stretch Database for a table, data migration stops and query results no longer include results from the remote table. The Customer table has the following DDL: The following command creates a new partition bound by the value 75, between 50 and 100. To verify that the default is applied, another value is inserted into the first column, and the table is queried. The following example uses the DISABLE TRIGGER option of ALTER TABLE to disable the trigger and allow for an insert that would typically violate the trigger. INDEX index_name This option doesn't apply to columnstore tables. This example populates the newly created period columns for system versioning using default values for the start and end times because these values can't be null. An offline index operation that creates, rebuilds, or drops a clustered index, or rebuilds or drops a nonclustered index, acquires a Schema modification (Sch-M) lock on the table. This command can't be canceled. scale In this example, the OrdersHistory table has the following two partitions and both partitions are empty: For the previous two tables, the following command moves all rows with OrderDate < '2004-01-01' from the Orders table to the OrdersHistory table. To run the DDL statement for an online index rebuild, all active blocking transactions running on a particular table must be completed. When using Always Encrypted (without secure enclaves), if the column being modified is encrypted with 'ENCRYPTED WITH', you can change the datatype to a compatible datatype (such as INT to BIGINT), but you can't change any encryption settings.

SPARSE By default, change tracking is disabled. Specifies whether a single partition of the underlying tables and associated indexes is available for queries and data modification during the index operation. Specifies that one or more column definitions, computed column definitions, or table constraints are added. To return the current setting, query the data_compression column in the sys.partitions catalog view. Therefore, WITH NOCHECK is used to prevent the constraint from being validated against existing rows, and to allow for the constraint to be added.