ALTER INDEX (Transact-SQL)

Artikel
02/25/2025

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL database in Microsoft Fabric

Modifies an existing table or view index (rowstore, columnstore, or XML) by disabling, rebuilding, or reorganizing the index; or by setting options on the index.

Transact-SQL syntax conventions

Syntax

Syntax for SQL Server, Azure SQL Database, and Azure SQL Managed Instance.

ALTER INDEX { index_name | ALL } ON <object>
{
      REBUILD {
            [ PARTITION = ALL [ WITH ( <rebuild_index_option> [ , ...n ] ) ] ]
          | [ PARTITION = partition_number [ WITH ( <single_partition_rebuild_index_option> [ , ...n ] ) ] ]
      }
    | DISABLE
    | REORGANIZE  [ PARTITION = partition_number ] [ WITH ( <reorganize_option>  ) ]
    | SET ( <set_index_option> [ , ...n ] )
    | RESUME [ WITH (<resumable_index_option> [ , ...n ] ) ]
    | PAUSE
    | ABORT
}
[ ; ]

<object> ::=
{
    { database_name.schema_name.table_or_view_name | schema_name.table_or_view_name | table_or_view_name }
}

<rebuild_index_option> ::=
{
      PAD_INDEX = { ON | OFF }
    | FILLFACTOR = fillfactor
    | SORT_IN_TEMPDB = { ON | OFF }
    | IGNORE_DUP_KEY = { ON | OFF }
    | STATISTICS_NORECOMPUTE = { ON | OFF }
    | STATISTICS_INCREMENTAL = { ON | OFF }
    | ONLINE = { ON [ ( <low_priority_lock_wait> ) ] | OFF }
    | RESUMABLE = { ON | OFF }
    | MAX_DURATION = <time> [ MINUTES ]
    | ALLOW_ROW_LOCKS = { ON | OFF }
    | ALLOW_PAGE_LOCKS = { ON | OFF }
    | MAXDOP = max_degree_of_parallelism
    | DATA_COMPRESSION = { NONE | ROW | PAGE | COLUMNSTORE | COLUMNSTORE_ARCHIVE }
        [ ON PARTITIONS ( { <partition_number> [ TO <partition_number> ] } [ , ...n ] ) ]
    | XML_COMPRESSION = { ON | OFF }
        [ ON PARTITIONS ( { <partition_number> [ TO <partition_number> ] } [ , ...n ] ) ] }

<single_partition_rebuild_index_option> ::=
{
      SORT_IN_TEMPDB = { ON | OFF }
    | MAXDOP = max_degree_of_parallelism
    | RESUMABLE = { ON | OFF }
    | MAX_DURATION = <time> [ MINUTES ]
    | DATA_COMPRESSION = { NONE | ROW | PAGE | COLUMNSTORE | COLUMNSTORE_ARCHIVE }
    | XML_COMPRESSION = { ON | OFF }
    | ONLINE = { ON [ ( <low_priority_lock_wait> ) ] | OFF }
}

<reorganize_option> ::=
{
       LOB_COMPACTION = { ON | OFF }
    |  COMPRESS_ALL_ROW_GROUPS =  { ON | OFF }
}

<set_index_option> ::=
{
      ALLOW_ROW_LOCKS = { ON | OFF }
    | ALLOW_PAGE_LOCKS = { ON | OFF }
    | OPTIMIZE_FOR_SEQUENTIAL_KEY = { ON | OFF }
    | IGNORE_DUP_KEY = { ON | OFF }
    | STATISTICS_NORECOMPUTE = { ON | OFF }
    | COMPRESSION_DELAY = { 0 | delay [ Minutes ] }
}

<resumable_index_option> ::=
 {
    MAXDOP = max_degree_of_parallelism
    | MAX_DURATION = <time> [ MINUTES ]
    | <low_priority_lock_wait>
 }

<low_priority_lock_wait> ::=
{
    WAIT_AT_LOW_PRIORITY ( MAX_DURATION = <time> [ MINUTES ] ,
                          ABORT_AFTER_WAIT = { NONE | SELF | BLOCKERS } )
}

Syntax for Azure Synapse Analytics and Analytics Platform System (PDW).

ALTER INDEX { index_name | ALL }
    ON [ schema_name. ] table_name
{
      REBUILD {
            [ PARTITION = ALL [ WITH ( <rebuild_index_option> ) ] ]
          | [ PARTITION = partition_number [ WITH ( <single_partition_rebuild_index_option> ) ] ]
      }
    | DISABLE
    | REORGANIZE [ PARTITION = partition_number ]
}
[ ; ]

<rebuild_index_option> ::=
{
    DATA_COMPRESSION = { COLUMNSTORE | COLUMNSTORE_ARCHIVE }
        [ ON PARTITIONS ( { <partition_number> [ TO <partition_number> ] } [ , ...n ] ) ]
    | XML_COMPRESSION = { ON | OFF }
        [ ON PARTITIONS ( { <partition_number> [ TO <partition_number> ] } [ , ...n ] ) ]
}

<single_partition_rebuild_index_option> ::=
{
    DATA_COMPRESSION = { COLUMNSTORE | COLUMNSTORE_ARCHIVE }
    | XML_COMPRESSION = { ON | OFF }
}

Arguments

index_name

The name of the index. Index names must be unique within a table or view but don't have to be unique within a database. Index names must follow the rules of identifiers.

ALL

Specifies all indexes associated with the table or view regardless of the index type. Specifying ALL causes the statement to fail if one or more indexes are in an offline or read-only filegroup or the specified operation isn't allowed on one or more index types. The following table lists the index operations and disallowed index types.

Using the keyword `ALL` with this operation	Fails if the table has one or more
`REBUILD WITH ONLINE = ON`	XML index Spatial index Columnstore index in SQL Server 2017 (14.x) and older versions only. Later versions support online rebuild of columnstore indexes.
`REBUILD PARTITION = <partition_number>`	Nonpartitioned index, XML index, spatial index, or disabled index
`REORGANIZE`	Indexes with `ALLOW_PAGE_LOCKS` set to `OFF`
`REORGANIZE PARTITION = <partition_number>`	Nonpartitioned index, XML index, spatial index, or disabled index
`IGNORE_DUP_KEY = ON`	XML index Spatial index Columnstore index ¹
`ONLINE = ON`	XML index Spatial index Columnstore index ¹
`RESUMABLE = ON`	Resumable indexes not supported with the `ALL` keyword

If ALL is specified with PARTITION = <partition_number>, all indexes must be aligned. This means that they're partitioned based on equivalent partition functions. Using ALL with PARTITION causes all index partitions with the same <partition_number> to be rebuilt or reorganized. For more information about partitioned indexes, see Partitioned tables and indexes.

For more information about online index operations, see Guidelines for online index operations.

database_name

The name of the database.

schema_name

The name of the schema to which the table or view belongs.

table_or_view_name

The name of the table or view associated with the index. To view index details for a table or view, use the sys.indexes catalog view.

Azure SQL Database supports the three-part name format <database_name>.<schema_name>.<object_name> when <database_name> is the current database name, or <database_name> is tempdb and <object_name> starts with # or ##. If the schema name is dbo, <schema_name> can be omitted.

REBUILD [ WITH ( <rebuild_index_option> [ ,... n ] ) ]

Applies to: SQL Server 2012 (11.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Specifies that the index is rebuilt using the same columns, index type, uniqueness attribute, and sort order. REBUILD enables a disabled index. Rebuilding a clustered index doesn't rebuild associated nonclustered indexes unless the keyword ALL is specified. If index options aren't specified, the existing index option values in sys.indexes are applied. For any index option whose value doesn't appear in sys.indexes, the default indicated in the argument definition of the option applies.

If ALL is specified and the underlying table is a heap, the rebuild operation has no effect on the heap. Any nonclustered indexes associated with the table are rebuilt.

The REBUILD operation can be minimally logged if the database recovery model is either bulk-logged or simple.

When you rebuild a primary XML index, the underlying user table is unavailable for the duration of the index operation.

For columnstore indexes, the rebuild operation:

Recompresses all data into the columnstore. Two copies of the columnstore index exist while the rebuild operation is in progress. When the rebuild is finished, Database Engine deletes the original columnstore index.
Doesn't preserve the sort order, if any. To rebuild a columnstore index and preserve or introduce a sort order, use the CREATE [CLUSTERED] COLUMNSTORE INDEX ... ORDER (...) ... WITH (DROP_EXISTING = ON) statement.

For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.

PARTITION

Specifies that only one partition of an index is rebuilt or reorganized. PARTITION can't be specified if index_name isn't a partitioned index.

PARTITION = ALL rebuilds all partitions.

Warning

Creating and rebuilding nonaligned indexes on a table with more than 1,000 partitions is possible, but isn't supported. Doing so might cause degraded performance or excessive memory consumption during these operations. Microsoft recommends using only aligned indexes when the number of partitions exceeds 1,000.

partition_number

The partition number of a partitioned index that is to be rebuilt or reorganized. partition_number is a constant expression that can reference variables. These include user-defined type variables or functions and user-defined functions, but can't reference a Transact-SQL statement. partition_number must exist or the statement fails.
WITH ( <single_partition_rebuild_index_option> )

SORT_IN_TEMPDB, MAXDOP, DATA_COMPRESSION, and XML_COMPRESSION are the options that can be specified when you rebuild a single partition using the (PARTITION = partition_number) syntax. XML indexes can't be specified in a single partition rebuild operation.

DISABLE

Marks the index as disabled and unavailable for use by the Database Engine. Any index can be disabled. The index definition of a disabled index remains in the system catalog with no underlying index data. Disabling a clustered index prevents user access to the underlying table data. To enable an index, use ALTER INDEX REBUILD or CREATE INDEX WITH DROP_EXISTING. For more information, see Disable indexes and constraints and Enable indexes and constraints.

REORGANIZE a rowstore index

For rowstore indexes, REORGANIZE specifies to reorganize the index leaf level. The REORGANIZE operation is:

Always performed online. This means long-term blocking table locks aren't held and queries or updates to the data in the underlying table can continue during the ALTER INDEX REORGANIZE transaction.
Not allowed for a disabled index.
Not allowed when ALLOW_PAGE_LOCKS is set to OFF.
Not rolled back when performed within a transaction and the transaction is rolled back.

Note

When ALTER INDEX REORGANIZE uses explicit transactions (for example, ALTER INDEX inside a BEGIN TRAN ... COMMIT/ROLLBACK) instead of the default implicit transaction mode, the locking behavior of REORGANIZE becomes more restrictive, potentially causing blocking. For more information about implicit transactions, see SET IMPLICIT_TRANSACTIONS.

For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.

REORGANIZE WITH ( LOB_COMPACTION = { ON | OFF } )

Applies to rowstore indexes.

ON
- Specifies to compact all pages that contain data of these large object (LOB) data types: image, text, ntext, varchar(max), nvarchar(max), varbinary(max), and xml. Compacting this data can reduce the data size on disk.
- For a clustered index, this compacts all LOB columns that are contained in the table.
- For a nonclustered index, this compacts all LOB columns that are nonkey (included) columns in the index.
- REORGANIZE ALL performs LOB compaction on all indexes. For each index, this compacts all LOB columns in the clustered index, underlying table, or included columns in a nonclustered index.
OFF
- Pages that contain large object data aren't compacted.
- OFF has no effect on a heap.

REORGANIZE a columnstore index

For columnstore indexes, REORGANIZE compresses each closed delta rowgroup into the columnstore as a compressed rowgroup. The REORGANIZE operation is always performed online. This means long-term blocking table locks aren't held and queries or updates to the underlying table can continue during the ALTER INDEX REORGANIZE transaction.

For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.

REORGANIZE isn't required in order to move the closed delta rowgroups into compressed rowgroups. The background tuple-mover (TM) process wakes up periodically to compress the closed delta rowgroups. We recommend using REORGANIZE when tuple-mover is falling behind. REORGANIZE can compress rowgroups more aggressively.
To compress all open and closed rowgroups, see the REORGANIZE WITH (COMPRESS_ALL_ROW_GROUPS).

For columnstore indexes in SQL Server 2016 (13.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance, REORGANIZE performs the following extra defragmentation optimizations online:

Physically removes deleted rows from a rowgroup when 10% or more of the rows have been logically deleted. The deleted bytes are reclaimed on the physical media. For example, if a compressed row group of 1 million rows has 100,000 rows deleted, the Database Engine removes the deleted rows and recompresses the rowgroup with 900,000 rows.
Combines one or more compressed rowgroups to increase rows per rowgroup up to the maximum of 1,048,576 rows. For example, if you bulk import 5 batches of 102,400 rows, you get 5 compressed rowgroups. If you run REORGANIZE, these rowgroups get merged into 1 compressed rowgroup with 512,000 rows. This assumes there are no dictionary size or memory limitations.
For rowgroups in which 10% or more of the rows have been logically deleted, the Database Engine tries to combine this rowgroup with one or more rowgroups. For example, rowgroup 1 is compressed with 500,000 rows and rowgroup 21 is compressed with the maximum of 1,048,576 rows. Rowgroup 21 has 60% of the rows deleted which leaves 409,830 rows. The Database Engine favors combining these two rowgroups to compress a new rowgroup that has 909,830 rows.

REORGANIZE WITH ( COMPRESS_ALL_ROW_GROUPS = { ON | OFF } )

Applies to columnstore indexes.

Applies to: SQL Server 2016 (13.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

COMPRESS_ALL_ROW_GROUPS provides a way to force open or closed delta rowgroups into the columnstore. With this option, it isn't necessary to rebuild the columnstore index to empty the delta rowgroups. Combined with the other remove and merge defragmentation features, this makes it no longer necessary to rebuild a columnstore index in most situations.

ON

Forces all rowgroups into the columnstore, regardless of size and state (closed or open).
OFF

Forces all closed rowgroups into the columnstore.

For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.

SET ( <set_index option> [ ,... n ] )

Modifies index options without rebuilding or reorganizing the index. SET can't be specified for a disabled index.

PAD_INDEX = { ON | OFF }

Specifies index padding. The default is OFF.

ON

The percentage of free space that is specified by fill factor is applied to the intermediate-level pages of the index. If FILLFACTOR isn't specified at the same time PAD_INDEX is set to ON, the fill factor value in sys.indexes is used.
OFF

The intermediate-level pages are filled to near capacity, leaving sufficient space for at least one row of the maximum size the index can have, considering the set of keys on the intermediate pages. This also occurs if PAD_INDEX is set to ON but fill factor isn't specified.

For more information, see CREATE INDEX.

FILLFACTOR = fillfactor

Specifies a percentage that indicates how full the Database Engine should make the leaf level of each index page during index creation or alteration. The value for fillfactor must be an integer value from 1 to 100. The default is 0. Fill factor values 0 and 100 are the same in all respects.

An explicit FILLFACTOR setting applies only when the index is first created or rebuilt. The Database Engine doesn't dynamically keep the specified percentage of empty space in the pages. For more information, see CREATE INDEX.

To view the fill factor setting, use fill_factor in sys.indexes.

Important

Creating an index with a FILLFACTOR less than 100 increases the amount of storage space the data occupies because the Database Engine redistributes the data according to the fill factor when it creates or rebuilds an index.

SORT_IN_TEMPDB = { ON | OFF }

Specifies whether to store temporary sort results in tempdb. The default is OFF except for Azure SQL Database Hyperscale. For all index build operations in Hyperscale, SORT_IN_TEMPDB is always ON unless a resumable index build is used. For resumable index builds, SORT_IN_TEMPDB is always OFF.

ON

The intermediate sort results that are used to build the index are stored in tempdb. This might reduce the time required to create an index. However, this increases the amount of disk space that is used during the index build.
OFF

The intermediate sort results are stored in the same database as the index.

If a sort operation isn't required, or if the sort can be performed in memory, the SORT_IN_TEMPDB option is ignored.

For more information, see SORT_IN_TEMPDB option for indexes.

IGNORE_DUP_KEY = { ON | OFF }

Specifies the error response when an insert operation attempts to insert duplicate key values into a unique index. The IGNORE_DUP_KEY option applies only to insert operations after the index is created or rebuilt. The default is OFF.

ON

A warning message occurs when duplicate key values are inserted into a unique index. Only the rows violating the uniqueness constraint aren't inserted.
OFF

An error message occurs when duplicate key values are inserted into a unique index. The entire INSERT operation is rolled back.

IGNORE_DUP_KEY can't be set to ON for indexes created on a view, non-unique indexes, XML indexes, spatial indexes, and filtered indexes.

To view the IGNORE_DUP_KEY setting for an index, use the ignore_dup_key column in the sys.indexes catalog view.

In backward compatible syntax, WITH IGNORE_DUP_KEY is equivalent to WITH IGNORE_DUP_KEY = ON.

STATISTICS_NORECOMPUTE = { ON | OFF }

Disable or enable the automatic statistics update option, AUTO_STATISTICS_UPDATE, for the statistics on the index. The default is OFF.

ON

Automatic statistics updates are disabled after the index is rebuilt.
OFF

Automatic statistics updates are enabled after the index is rebuilt.

To restore automatic statistics updating, set the STATISTICS_NORECOMPUTE to OFF, or execute UPDATE STATISTICS without the NORECOMPUTE clause.

Warning

If you disable automatic recomputation of statistics by setting STATISTICS_NORECOMPUTE = ON, you might prevent the query optimizer from picking optimal execution plans for queries involving the table.

Setting STATISTICS_NORECOMPUTE to ON doesn't prevent the update of index statistics that occurs during the index rebuild operation.

STATISTICS_INCREMENTAL = { ON | OFF }

Applies to: SQL Server 2014 (12.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

When ON, the statistics created on the index are per partition statistics. When OFF, the existing statistics is dropped and the Database Engine recomputes the statistics. The default is OFF.

If per partition statistics aren't supported, the option is ignored and a warning is generated. Incremental statistics aren't supported in the following cases:

Statistics created with indexes that aren't partition-aligned with the base table
Statistics created on availability group readable secondary databases
Statistics created on read-only databases
Statistics created on filtered indexes
Statistics created on views
Statistics created on internal tables
Statistics created with spatial indexes or XML indexes

ONLINE = { ON | OFF }

Specifies whether underlying tables and associated indexes are available for queries and data modification during the index operation. The default is OFF.

For an XML index or spatial index, only ONLINE = OFF is supported, and if ONLINE is set to ON an error is raised.

Important

Online index operations aren't available in every edition of Microsoft SQL Server. For a list of features that are supported by the editions of SQL Server, see Editions and supported features of SQL Server 2022.

ON

Long-term table locks are not held for the duration of the index operation. During the main phase of the index operation, only an intent shared (IS) lock is held on the source table. This enables queries or updates to the underlying table and indexes to proceed. At the start of the operation, a shared (S) lock is held on the source object for a short period of time. At the end of the operation, for a short period of time, a shared (S) lock is acquired on the object if a nonclustered index is being created. A schema modification (Sch-M) lock is acquired when a clustered index is created or dropped online and when a clustered or nonclustered index is being rebuilt. ONLINE can't be set to ON when an index is being created on a local temporary table.

Note

You can use the WAIT_AT_LOW_PRIORITY option to reduce or avoid blocking during online index operations. For more information, see WAIT_AT_LOW_PRIORITY with online index operations.
OFF

Table locks are applied for the duration of the index operation. An offline index operation that creates, rebuilds, or drops a clustered, spatial, or XML index, or rebuilds or drops a nonclustered index, acquires a schema modification (Sch-M) lock on the table. This prevents all user access to the underlying table for the duration of the operation. An offline index operation that creates a nonclustered index initially acquires a shared (S) lock on the table. This prevents modifications of the underlying table definition, but allows reading and modifying the data in the table while the index build is in progress.

For more information, see Perform index operations online and Guidelines for online index operations.

Indexes, including indexes on global temp tables, can be rebuilt online except for the following cases:

XML index
Index on a local temp table
Initial unique clustered index on a view
Disabled clustered indexes
Clustered columnstore indexes in SQL Server 2017 (14.x)) and earlier versions
Nonclustered columnstore indexes in SQL Server 2016 (13.x)) and earlier versions
Clustered index, if the underlying table contains LOB data types (image, ntext, text) and spatial data types
varchar(max) and varbinary(max) columns can't be part of an index key. In SQL Server (starting with SQL Server 2012 (11.x)), in Azure SQL Database and in Azure SQL Managed Instance, when a table contains varchar(max) or varbinary(max) columns, a clustered index containing other columns can be built or rebuilt using the ONLINE option.

For more information, see How online index operations work.

RESUMABLE = { ON | OFF}

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Specifies whether an online index operation is resumable.

ON

Index operation is resumable.
OFF

Index operation isn't resumable.

MAX_DURATION = time [ MINUTES ] used with `RESUMABLE = ON` (requires `ONLINE = ON`)

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Specifies for how long, in integer minutes, a resumable index operation is executed before it's paused.

ALLOW_ROW_LOCKS = { ON | OFF }

Specifies whether row locks are allowed. The default is ON.

ON

Row locks are allowed when accessing the index. The Database Engine determines when row locks are used.
OFF

Row locks aren't used.

ALLOW_PAGE_LOCKS = { ON | OFF }

Specifies whether page locks are allowed. The default is ON.

ON

Page locks are allowed when you access the index. The Database Engine determines when page locks are used.
OFF

Page locks aren't used.

OPTIMIZE_FOR_SEQUENTIAL_KEY = { ON | OFF }

Applies to: SQL Server 2019 (15.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Specifies whether or not to optimize to avoid last-page insert contention. The default is OFF. For more information, see Sequential keys.

MAXDOP = max_degree_of_parallelism

Overrides the max degree of parallelism configuration option for the index operation. For more information, see Configure the max degree of parallelism Server Configuration Option. Use MAXDOP to limit the degree of parallelism and the resulting resource consumption for an index build operation.

Although the MAXDOP option is syntactically supported for all XML indexes and spatial indexes, ALTER INDEX currently uses only a single processor.

max_degree_of_parallelism can be:

1

Suppresses parallel plan generation.
>1

Restricts the maximum degree of parallelism used in a parallel index operation to the specified number or less based on the current system workload.
0 (default)

Uses the degree of parallelism specified at the server, database, or workload group level, unless reduced based on the current system workload.

For more information, see Configure parallel index operations.

Note

Parallel index operations aren't available in every edition of SQL Server. For a list of features that are supported by the editions of SQL Server, see Editions and supported features of SQL Server 2022.

COMPRESSION_DELAY = { 0 | duration [ minutes ] }

Applies to: SQL Server (starting with SQL Server 2016 (13.x)), Azure SQL Database, and Azure SQL Managed Instance

For a disk-based table with a columnstore index, specifies the minimum number of minutes a delta rowgroup in the closed state must remain in the delta store before the Database Engine can compress it into a compressed rowgroup. Since disk-based tables don't track insert and update times on individual rows, the Database Engine applies this delay only to delta store rowgroups in the closed state.

The default is 0 minutes.

For recommendations on when to use COMPRESSION_DELAY, see Get started with columnstore for real-time operational analytics.

DATA_COMPRESSION

Specifies the data compression option for the specified index, partition number, or range of partitions. The options are as follows:

NONE

Index or specified partitions aren't compressed. This doesn't apply to columnstore indexes.
ROW

Index or specified partitions are compressed by using row compression. This doesn't apply to columnstore indexes.
PAGE

Index or specified partitions are compressed by using page compression. This doesn't apply to columnstore indexes.
COLUMNSTORE

Applies to: SQL Server 2014 (12.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Applies only to columnstore indexes, including both nonclustered columnstore and clustered columnstore indexes. Specifying COLUMNSTORE removes all other data compression including COLUMNSTORE_ARCHIVE.
COLUMNSTORE_ARCHIVE

Applies to: SQL Server 2014 (12.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Applies only to columnstore indexes, including both nonclustered columnstore and clustered columnstore indexes. COLUMNSTORE_ARCHIVE further compresses the specified partition to a smaller size. This can be used for archival, or for other situations that require a smaller storage size and can afford more time for storage and retrieval.

For more information about compression, see Data compression.

XML_COMPRESSION

Applies to: SQL Server 2022 (16.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Specifies the XML compression option for the specified index that contains one or more xml data type columns. The options are as follows:

ON

Index or specified partitions are compressed by using XML compression.
OFF

Index or specified partitions aren't compressed.

ON PARTITIONS ( { <partition_number_expression> | <range> } [ ,...n ] )

Specifies the partitions to which the DATA_COMPRESSION or XML_COMPRESSION settings apply. If the index isn't partitioned, the ON PARTITIONS argument generates an error. If the ON PARTITIONS clause isn't provided, the DATA_COMPRESSION or XML_COMPRESSION option applies to all partitions of a partitioned index.

<partition_number_expression> can be specified in the following ways:

Provide the number for a partition, for example: ON PARTITIONS (2).
Provide the partition numbers for several individual partitions separated by commas, for example: ON PARTITIONS (1, 5).
Provide both ranges and individual partitions: ON PARTITIONS (2, 4, 6 TO 8).

<range> can be specified as partition numbers separated by the word TO, for example: ON PARTITIONS (6 TO 8).

To set different types of data compression for different partitions, specify the DATA_COMPRESSION option more than once, for example:

REBUILD WITH
(
DATA_COMPRESSION = NONE ON PARTITIONS (1),
DATA_COMPRESSION = ROW ON PARTITIONS (2, 4, 6 TO 8),
DATA_COMPRESSION = PAGE ON PARTITIONS (3, 5)
);

You can also specify the XML_COMPRESSION option more than once, for example:

REBUILD WITH
(
XML_COMPRESSION = OFF ON PARTITIONS (1),
XML_COMPRESSION = ON ON PARTITIONS (2, 4, 6 TO 8),
XML_COMPRESSION = OFF ON PARTITIONS (3, 5)
);

RESUME

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Resumes an index operation that is paused manually, because the maximum duration is reached, or because of a failure.

MAX_DURATION

Specifies for how long, in integer minutes, a resumable index operation is executed after being resumed before it's paused again.
WAIT_AT_LOW_PRIORITY

Resuming an index build operation after a pause has to acquire the necessary locks. WAIT_AT_LOW_PRIORITY indicates that the index build operation acquires low priority locks, which allow other operations to proceed while the index build operation is waiting. Omitting the WAIT_AT_LOW_PRIORITY option is equivalent to WAIT_AT_LOW_PRIORITY (MAX_DURATION = 0 minutes, ABORT_AFTER_WAIT = NONE). For more information, see WAIT_AT_LOW_PRIORITY.

PAUSE

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Pauses a resumable index build operation.

ABORT

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

Aborts a running or paused index build operation that was started as resumable. You must explicitly execute an ABORT command to terminate a resumable index build operation. A failure or a pause in a resumable index operation doesn't terminate its execution; rather, it leaves the operation in an indefinite pause state.

Remarks

ALTER INDEX can't be used to repartition an index or move it to a different filegroup. This statement can't be used to modify the index definition, such as adding or deleting columns or changing the column order. Use CREATE INDEX with the DROP_EXISTING clause to perform these operations.

When an option isn't explicitly specified, the current setting is applied. For example, if a FILLFACTOR setting isn't specified in the REBUILD clause, the fill factor value stored in the system catalog is used during the rebuild process. To view the current index option settings, use sys.indexes.

The values for ONLINE, MAXDOP, and SORT_IN_TEMPDB aren't stored in the system catalog. Unless specified in the index statement, the default value for the option is used.

On multiprocessor computers, just like other queries do, ALTER INDEX REBUILD automatically uses more processors to perform the scan and sort operations that are associated with modifying the index. Conversely, ALTER INDEX REORGANIZE is a single threaded operation. For more information, see Configure parallel index operations.

In SQL database in Microsoft Fabric, ALTER INDEX ALL is not supported, but ALTER INDEX <index name> is.

Rebuild indexes

Rebuilding an index drops and re-creates the index. This removes fragmentation, reclaims disk space by compacting the pages based on the specified or existing fill factor setting, and reorders the index rows in contiguous pages. When ALL is specified, all indexes on the table are dropped and rebuilt in a single transaction. Foreign key constraints don't have to be dropped in advance. When indexes with 128 extents or more are rebuilt, the Database Engine defers the actual page deallocations, and their associated locks, until after the transaction commits. For more information, see Deferred deallocation.

For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.

Reorganize indexes

Reorganizing an index uses minimal system resources. It defragments the leaf level of clustered and nonclustered indexes on tables and views by physically reordering the leaf-level pages to match the logical, left to right, order of the leaf nodes. Reorganizing also compacts the index pages. Compaction is based on the existing fill factor value.

When ALL is specified, relational indexes, both clustered and nonclustered, and XML indexes on the table are reorganized. Some restrictions apply when specifying ALL.

For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.

Note

For an Azure Synapse Analytics table with an ordered clustered columnstore index, ALTER INDEX REORGANIZE doesn't re-sort the data. To resort the data use ALTER INDEX REBUILD.

Disable indexes

Disabling an index prevents user access to the index, and for clustered indexes, to the underlying table data. The index definition remains in the system catalog. Disabling a nonclustered index or clustered index on a view physically deletes the index data. Disabling a clustered index prevents access to the data, but the data remains unmaintained in the B-tree until the index is dropped or rebuilt. To see if an index is disabled, use the is_disabled column in the sys.indexes catalog view.

Note

Documentation uses the term B-tree generally in reference to indexes. In rowstore indexes, the Database Engine implements a B+ tree. This does not apply to columnstore indexes or indexes on memory-optimized tables. For more information, see the SQL Server and Azure SQL index architecture and design guide.

If a table is in a transactional replication publication, you can't disable an index that is associated with a primary key constraint. These indexes are required by replication. To disable such an index, you must first drop the table from the publication. For more information, see Publish data and database objects.

Use the ALTER INDEX REBUILD statement or the CREATE INDEX WITH DROP_EXISTING statement to enable the index. Rebuilding a disabled clustered index can't be performed with the ONLINE option set to ON. For more information, see Disable indexes and constraints.

Set options

You can set the options ALLOW_ROW_LOCKS, ALLOW_PAGE_LOCKS, OPTIMIZE_FOR_SEQUENTIAL_KEY, IGNORE_DUP_KEY, and STATISTICS_NORECOMPUTE for a specified index without rebuilding or reorganizing that index. The modified values are immediately applied to the index. To view these settings, use sys.indexes. For more information, see Set index options.

Row and page locks options

When ALLOW_ROW_LOCKS = ON and ALLOW_PAGE_LOCK = ON, row-level, page-level, and table-level locks are allowed when you access the index. The Database Engine chooses the appropriate lock and can escalate the lock from a row or page lock to a table lock.

When ALLOW_ROW_LOCKS = OFF and ALLOW_PAGE_LOCK = OFF, only a table-level lock is allowed when you access the index.

If ALL is specified when the row or page lock options are set, the settings are applied to all indexes. When the underlying table is a heap, the settings are applied in the following ways:

Option	Applies to
`ALLOW_ROW_LOCKS = ON` or `OFF`	The heap and all associated nonclustered indexes.
`ALLOW_PAGE_LOCKS = ON`	The heap and all associated nonclustered indexes.
`ALLOW_PAGE_LOCKS = OFF`	The nonclustered indexes, where all page locks aren't allowed. For the heap, only the shared (`S`), update (`U`) and exclusive (`X`) page locks aren't allowed. The Database Engine can still acquire intent page locks (`IS`, `IU`, or `IX`) for internal purposes.

Warning

It is not recommended to disable row or page locks on an index. Concurrency-related problems might occur, and certain functionality might be unavailable. For example, an index can't be reorganized when ALLOW_PAGE_LOCKS is set to OFF.

Online index operations

When rebuilding an index and the ONLINE option is set to ON, data in the index, its associated table, and other indexes on the same table is available for queries and modification. You can also rebuild online a portion of an index residing on a single partition. Exclusive table locks are held only for a short amount of time at the end of the index rebuild.

Reorganizing an index is always performed online. The process holds locks only for short periods of time and is unlikely to block queries or updates.

You can perform concurrent online index operations on the same table or table partition only when doing the following operations:

Creating multiple nonclustered indexes.
Reorganizing different indexes on the same table.
Reorganizing different indexes while rebuilding nonoverlapping indexes on the same table.

All other online index operations performed at the same time fail. For example, you can't rebuild two or more indexes on the same table concurrently, or create a new index while rebuilding an existing index on the same table.

For more information, see Perform index operations online.

Resumable index operations

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

You can make an online index rebuild resumable. That means that the index rebuild can be stopped and later restarted from the point where it stopped. To run an index rebuild as resumable, specify the RESUMABLE = ON option.

The following guidelines apply to resumable index operations:

To use the RESUMABLE option you must also use the ONLINE option.
The RESUMABLE option isn't persisted in the metadata for a given index and applies only to the duration of the current DDL statement. Therefore, the RESUMABLE = ON clause must be specified explicitly to enable resumability.
The MAX_DURATION option can be specified in two contexts:
- MAX_DURATION for the RESUMABLE option specifies the time interval for an index being built. After this time elapses, and if the index build is still running, it is paused. You decide when the build for a paused index can be resumed. The time in minutes for MAX_DURATION must be greater than 0 minutes and less than or equal to one week (7 * 24 * 60 = 10080 minutes). A long pause in an index operation might noticeably impact the DML performance on a specific table as well as the database disk capacity since both the original index and the newly created index require disk space and need to be updated by DML operations. If MAX_DURATION option is omitted, the index operation continues until completion or until a failure occurs.
- MAX_DURATION for the WAIT_AT_LOW_PRIORITY option specifies the time to wait using low priority locks if the index operation is blocked, before taking action. For more information, see WAIT_AT_LOW_PRIORITY with online index operations.
To pause the index operation immediately, you can execute the ALTER INDEX PAUSE command, or execute the KILL <session_id> command.
Re-executing the original ALTER INDEX REBUILD statement with the same parameters resumes a paused index rebuild operation. You can also resume a paused index rebuild operation by executing the ALTER INDEX RESUME statement.
The ABORT command kills the session that is running an index build and cancels the index operation. You cannot resume an index operation that has been aborted.
When resuming an index rebuild operation that is paused, you can change the MAXDOP value to a new value. If MAXDOP isn't specified when resuming an index operation that is paused, the MAXDOP value used for the last resume is used. If the MAXDOP option isn't specified at all for an index rebuild operation, then the default value is used.

A resumable index operation runs until it completes, pauses, or fails. In case the operation pauses, an error is issued indicating that the operation was paused and that the index rebuild did not complete. In case the operation fails, an error is issued as well.

To see if an index operation is executed as a resumable operation and to check its current execution state, use the sys.index_resumable_operations catalog view.

Resources

The following resources are required for resumable index operations:

Additional space required to keep the index being built, including the time when build is paused.
Additional log throughput during the sorting phase. The overall log space usage for resumable index is less compared to regular online index rebuild and allows log truncation during this operation.
DDL statements attempting to modify an index that is being rebuild or its associated table while the index operation is paused aren't allowed.
Ghost cleanup is blocked on the in-build index for the duration of the operation both while paused and while the operation is running.
If the table contains LOB columns, a resumable clustered index build requires a schema modification (Sch-M) lock at the start of the operation.

Current functional limitations

Resumable index rebuild operations have the following limitations:

The SORT_IN_TEMPDB = ON option isn't supported for resumable index operations.
The DDL command with RESUMABLE = ON can't be executed inside an explicit transaction.
You cannot create a resumable index that contains:
- Computed or timestamp/rowversion columns as key columns.
- LOB column as an included column.
Resumable index operations aren't supported for:
- The ALTER INDEX REBUILD ALL command
- The ALTER TABLE REBUILD command
- Columnstore indexes
- Filtered indexes
- Disabled indexes

WAIT_AT_LOW_PRIORITY with online index operations

Applies to: SQL Server 2014 (12.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

When you don't use the WAIT_AT_LOW_PRIORITY option, all active blocking transactions holding locks on the table or index must complete for the index rebuild operation to start and to complete. When the online index operation starts and before it completes, it needs to acquire a shared (S) or a schema modification (Sch-M) lock on the table and hold it for a short time. Even though the lock is held for a short time only, it might significantly affect workload throughput, increase query latency, or cause execution time-outs.

To avoid these problems, the WAIT_AT_LOW_PRIORITY option allows you to manage the behavior of S or Sch-M locks required for an online index operation to start and complete, selecting from three options. In all cases, if during the wait time specified by MAX_DURATION = n [minutes] there is no blocking that involves the index operation, the index operation proceeds immediately.

WAIT_AT_LOW_PRIORITY makes the online index operation wait using low priority locks, allowing other operations using normal priority locks to proceed in the meantime. Omitting the WAIT_AT_LOW_PRIORITY option is equivalent to WAIT_AT_LOW_PRIORITY (MAX_DURATION = 0 minutes, ABORT_AFTER_WAIT = NONE).

MAX_DURATION = time [MINUTES]

The wait time (an integer value specified in minutes) that the online index operation waits using low priority locks. If the operation is blocked for the MAX_DURATION time, the specified ABORT_AFTER_WAIT action is executed. MAX_DURATION time is always in minutes, and the word MINUTES can be omitted.

ABORT_AFTER_WAIT = [NONE | SELF | BLOCKERS ]

NONE: Continue waiting for the lock with normal priority.
SELF: Exit the online index operation currently being executed, without taking any action. The option SELF can't be used when MAX_DURATION is 0.
BLOCKERS: Kill all user transactions that block the online index operation so that the operation can continue. The BLOCKERS option requires the principal executing the CREATE INDEX or ALTER INDEX statement to have the ALTER ANY CONNECTION permission.

You can use the following extended events to monitor index operations that wait for locks at low priority:

lock_request_priority_state
process_killed_by_abort_blockers
ddl_with_wait_at_low_priority

Spatial index restrictions

When you rebuild a spatial index, the underlying user table is unavailable during the index operation.

The PRIMARY KEY constraint in the user table can't be modified while a spatial index is defined on a column of that table. To change the PRIMARY KEY constraint, first drop every spatial index of the table. After modifying the PRIMARY KEY constraint, you can re-create each of the spatial indexes.

In a single partition rebuild operation, you can't specify any spatial indexes. However, you can specify spatial indexes in a table rebuild.

To change options that are specific to a spatial index, such as BOUNDING_BOX or GRID, you can either use a CREATE SPATIAL INDEX statement that specifies DROP_EXISTING = ON, or drop the spatial index and create a new one. For an example, see CREATE SPATIAL INDEX.

Data compression

For a more information about data compression, see Data compression.

The following are the key points to consider in the context of index build operations when data compression is used:

Compression can allow more rows to be stored on a page, but doesn't change the maximum row size.
Non-leaf pages of an index are not page compressed but can be row compressed.
Each nonclustered index has an individual compression setting, and doesn't inherit the compression setting of the underlying table.
When a clustered index is created on a heap, the clustered index inherits the compression state of the heap unless an alternative compression state is specified.

The following considerations apply rebuilding partitioned indexes:

You can't change the compression setting of a single partition if the table has nonaligned indexes.
The ALTER INDEX <index> ... REBUILD PARTITION ... WITH DATA_COMPRESSION = ... syntax rebuilds the specified partition of the index with the specified compression option. If the WITH DATA_COMPRESSION clause is omitted, the existing compression option is used.
The ALTER INDEX <index> ... REBUILD PARTITION = ALL syntax rebuilds all partitions of the index using the existing compression options.
The ALTER INDEX <index> ... REBUILD PARTITION = ALL (WITH ...) syntax rebuilds all partitions of the index. You can choose different compression for different partitions using the DATA_COMPRESSION = ... ON PARTITIONS ( ...) clause.

To evaluate how changing PAGE and ROW compression affects a table, an index, or a partition, use the sp_estimate_data_compression_savings stored procedure.

Statistics

When you rebuild an index, the statistics on the index are updated with full scan for non-partitioned indexes, and with the default sampling ratio for partitioned indexes. No other statistics on the table are updated as a part of index rebuild.

Permissions

The ALTER permission on the table or view is required.

Version notes

Azure SQL Database doesn't support filegroups other than PRIMARY.
Azure SQL Database and Azure SQL Managed Instance don't support FILESTREAM options.
Columnstore indexes aren't available before SQL Server 2012 (11.x).
Resumable index operations are available in SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance.

Basic syntax example

ALTER INDEX index1 ON table1 REBUILD;
ALTER INDEX ALL ON table1 REBUILD;
ALTER INDEX ALL ON dbo.table1 REBUILD;

Examples: Columnstore indexes

These examples apply to columnstore indexes.

A. REORGANIZE demo

This example demonstrates how the ALTER INDEX REORGANIZE command works. It creates a table that has multiple rowgroups, and then demonstrates how REORGANIZE merges the rowgroups.

-- Create a database
CREATE DATABASE [columnstore];
GO

-- Create a rowstore staging table
CREATE TABLE [staging] (
    AccountKey INT NOT NULL,
    AccountDescription NVARCHAR(50),
    AccountType NVARCHAR(50),
    AccountCodeAlternateKey INT
);

-- Insert 10 million rows into the staging table.
DECLARE @loop INT;
DECLARE @AccountDescription VARCHAR(50);
DECLARE @AccountKey INT;
DECLARE @AccountType VARCHAR(50);
DECLARE @AccountCode INT;

SELECT @loop = 0

BEGIN TRANSACTION

WHILE (@loop < 300000)
BEGIN
    SELECT @AccountKey = CAST(RAND() * 10000000 AS INT);
    SELECT @AccountDescription = 'accountdesc ' + CONVERT(VARCHAR(20), @AccountKey);
    SELECT @AccountType = 'AccountType ' + CONVERT(VARCHAR(20), @AccountKey);
    SELECT @AccountCode = CAST(RAND() * 10000000 AS INT);

    INSERT INTO staging
    VALUES (
        @AccountKey,
        @AccountDescription,
        @AccountType,
        @AccountCode
     );

    SELECT @loop = @loop + 1;
END

COMMIT

-- Create a table for the clustered columnstore index
CREATE TABLE cci_target (
    AccountKey INT NOT NULL,
    AccountDescription NVARCHAR(50),
    AccountType NVARCHAR(50),
    AccountCodeAlternateKey INT
);

-- Convert the table to a clustered columnstore index named inxcci_cci_target;
CREATE CLUSTERED COLUMNSTORE INDEX idxcci_cci_target ON cci_target;

Use the TABLOCK option to insert rows in parallel. Starting with SQL Server 2016 (13.x), the INSERT INTO operation can run in parallel when TABLOCK is used.

INSERT INTO cci_target WITH (TABLOCK)
SELECT TOP 300000 * FROM staging;

Run this command to see the OPEN delta rowgroups. The number of rowgroups depends on the degree of parallelism.

SELECT *
FROM sys.dm_db_column_store_row_group_physical_stats
WHERE object_id  = object_id('cci_target');

Run this command to force all CLOSED and OPEN rowgroups into the columnstore.

ALTER INDEX idxcci_cci_target ON cci_target REORGANIZE WITH (COMPRESS_ALL_ROW_GROUPS = ON);

Run this command again and you see that smaller rowgroups are merged into one compressed rowgroup.

ALTER INDEX idxcci_cci_target ON cci_target REORGANIZE WITH (COMPRESS_ALL_ROW_GROUPS = ON);

B. Compress CLOSED delta rowgroups into the columnstore

This example uses the REORGANIZE option to compress each CLOSED delta rowgroup into the columnstore as a compressed rowgroup. This isn't necessary, but is useful when the tuple-mover isn't compressing CLOSED rowgroups fast enough.

You can run both example in the AdventureWorksDW2022 sample database.

This sample runs REORGANIZE on all partitions.

ALTER INDEX cci_FactInternetSales2 ON FactInternetSales2 REORGANIZE;

This sample runs REORGANIZE on a specific partition.

-- REORGANIZE a specific partition
ALTER INDEX cci_FactInternetSales2 ON FactInternetSales2 REORGANIZE PARTITION = 0;

C. Compress all OPEN AND CLOSED delta rowgroups into the columnstore

Applies to: SQL Server 2016 (13.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

The command REORGANIZE WITH (COMPRESS_ALL_ROW_GROUPS = ON) compresses each OPEN and CLOSED delta rowgroup into the columnstore as a compressed rowgroup. This empties the deltastore and forces all rows to get compressed into the columnstore. This is useful especially after performing many insert operations since these operations store the rows in one or more delta rowgroups.

REORGANIZE combines rowgroups to fill rowgroups up to a maximum number of rows <= 1,024,576. Therefore, when you compress all OPEN and CLOSED rowgroups you don't end up with lots of compressed rowgroups that only have a few rows in them. You want rowgroups to be as full as possible to reduce the compressed size and improve query performance.

The following examples use the AdventureWorksDW2022 database.

This example moves all OPEN and CLOSED delta rowgroups into the columnstore index.

ALTER INDEX cci_FactInternetSales2 ON FactInternetSales2 REORGANIZE WITH (COMPRESS_ALL_ROW_GROUPS = ON);

This example moves all OPEN and CLOSED delta rowgroups into the columnstore index for a specific partition.

ALTER INDEX cci_FactInternetSales2 ON FactInternetSales2 REORGANIZE PARTITION = 0 WITH (COMPRESS_ALL_ROW_GROUPS = ON);

D. Defragment a columnstore index online

Doesn't apply to: SQL Server 2012 (11.x) and SQL Server 2014 (12.x).

Starting with SQL Server 2016 (13.x), REORGANIZE does more than compress delta rowgroups into the columnstore. It also performs online defragmentation. First, it reduces the size of the columnstore by physically removing deleted rows when 10% or more of the rows in a rowgroup have been deleted. Then, it combines rowgroups together to form larger rowgroups that have up to the maximum of 1,024,576 rows per rowgroups. All rowgroups that are changed get recompressed.

Note

Starting with SQL Server 2016 (13.x), rebuilding a columnstore index is no longer necessary in most situations since REORGANIZE physically removes deleted rows and merges rowgroups. The COMPRESS_ALL_ROW_GROUPS option forces all OPEN or CLOSED delta rowgroups into the columnstore which previously could only be done with a rebuild. REORGANIZE is online and occurs in the background so queries can continue as the operation happens.

The following example performs a REORGANIZE to defragment the index by physically removing rows that have been logically deleted from the table, and merging rowgroups.

ALTER INDEX cci_FactInternetSales2 ON FactInternetSales2 REORGANIZE;

E. Rebuild a clustered columnstore index offline

Applies to: SQL Server, Azure SQL Database, and Azure SQL Managed Instance

Tip

Starting with SQL Server 2016 (13.x) and in Azure SQL Database, we recommend using ALTER INDEX REORGANIZE instead of ALTER INDEX REBUILD for columnstore indexes.

Note

In SQL Server 2012 (11.x) and SQL Server 2014 (12.x), REORGANIZE is only used to compress CLOSED rowgroups into the columnstore. The only way to perform defragmentation operations and to force all delta rowgroups into the columnstore is to rebuild the index.

This example shows how to rebuild a clustered columnstore index and force all delta rowgroups into the columnstore. This first step prepares a table FactInternetSales2 in the AdventureWorksDW2022 database with a clustered columnstore index, and inserts data from the first four columns.

CREATE TABLE dbo.FactInternetSales2 (
    ProductKey [int] NOT NULL,
    OrderDateKey [int] NOT NULL,
    DueDateKey [int] NOT NULL,
    ShipDateKey [int] NOT NULL);

CREATE CLUSTERED COLUMNSTORE INDEX cci_FactInternetSales2
ON dbo.FactInternetSales2;

INSERT INTO dbo.FactInternetSales2
SELECT ProductKey, OrderDateKey, DueDateKey, ShipDateKey
FROM dbo.FactInternetSales;

SELECT * FROM sys.column_store_row_groups;

The results show one OPEN rowgroup, which means SQL Server waits for more rows to be added before it closes the rowgroup and moves the data to the columnstore. This next statement rebuilds the clustered columnstore index, which forces all rows into the columnstore.

ALTER INDEX cci_FactInternetSales2 ON FactInternetSales2 REBUILD;
SELECT * FROM sys.column_store_row_groups;

The results of the SELECT statement show the rowgroup is COMPRESSED, which means the column segments of the rowgroup are now compressed and stored in the columnstore.

F. Rebuild a partition of a clustered columnstore index offline

Applies to: SQL Server 2012 (11.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

To rebuild a partition of a large clustered columnstore index, use ALTER INDEX REBUILD with the partition option. This example rebuilds partition 12. Starting with SQL Server 2016 (13.x), we recommend replacing REBUILD with REORGANIZE.

ALTER INDEX cci_fact3
ON fact3
REBUILD PARTITION = 12;

G. Change a clustered columnstore index to use archival compression

Doesn't apply to: SQL Server 2012 (11.x)

You can choose to reduce the size of a clustered columnstore index even further by using the COLUMNSTORE_ARCHIVE data compression option. This is practical for older data that you want to keep on cheaper storage. We recommend only using this on data that isn't accessed often since decompress is slower than with the normal COLUMNSTORE compression.

The following example rebuilds a clustered columnstore index to use archival compression, and then shows how to remove the archival compression. The final result uses only columnstore compression.

First, prepare the example by creating a table with a clustered columnstore index. Then, compress the table further by using archival compression.

--Prepare the example by creating a table with a clustered columnstore index.
CREATE TABLE SimpleTable (
    ProductKey [int] NOT NULL,
    OrderDateKey [int] NOT NULL,
    DueDateKey [int] NOT NULL,
    ShipDateKey [int] NOT NULL
);

CREATE CLUSTERED INDEX cci_SimpleTable ON SimpleTable (ProductKey);

CREATE CLUSTERED COLUMNSTORE INDEX cci_SimpleTable
ON SimpleTable
WITH (DROP_EXISTING = ON);

--Compress the table further by using archival compression.
ALTER INDEX cci_SimpleTable ON SimpleTable
REBUILD
WITH (DATA_COMPRESSION = COLUMNSTORE_ARCHIVE);
GO

This sample removes the archive compression, and only uses columnstore compression.

ALTER INDEX cci_SimpleTable ON SimpleTable
REBUILD
WITH (DATA_COMPRESSION = COLUMNSTORE);
GO

Examples: Rowstore indexes

A. Rebuild an index

The following example rebuilds a single index on the Employee table in the AdventureWorks2022 database.

ALTER INDEX PK_Employee_EmployeeID ON HumanResources.Employee REBUILD;

B. Rebuild all indexes on a table and specify options

The following example specifies the keyword ALL. This rebuilds all indexes associated with the table Production.Product in the AdventureWorks2022 database. Three options are specified.

ALTER INDEX ALL ON Production.Product
REBUILD WITH (FILLFACTOR = 80, SORT_IN_TEMPDB = ON, STATISTICS_NORECOMPUTE = ON);

The following example adds the ONLINE option including the low priority lock option, and adds the row compression option.

Applies to: SQL Server 2014 (12.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

ALTER INDEX ALL ON Production.Product
REBUILD WITH
(
    FILLFACTOR = 80,
    SORT_IN_TEMPDB = ON,
    STATISTICS_NORECOMPUTE = ON,
    ONLINE = ON ( WAIT_AT_LOW_PRIORITY ( MAX_DURATION = 4 MINUTES, ABORT_AFTER_WAIT = BLOCKERS ) ),
    DATA_COMPRESSION = ROW
);

C. Reorganize an index with LOB compaction

The following example reorganizes a single clustered index in the AdventureWorks2022 database. Because the index contains a LOB data type in the leaf level, the statement also compacts all pages that contain the large object data. Specifying the WITH (LOB_COMPACTION = ON) option isn't required because the default value is ON.

ALTER INDEX PK_ProductPhoto_ProductPhotoID ON Production.ProductPhoto REORGANIZE WITH (LOB_COMPACTION = ON);

D. Set options on an index

The following example sets several options on the index AK_SalesOrderHeader_SalesOrderNumber in the AdventureWorks2022 database.

ALTER INDEX AK_SalesOrderHeader_SalesOrderNumber ON
    Sales.SalesOrderHeader
SET (
    STATISTICS_NORECOMPUTE = ON,
    IGNORE_DUP_KEY = ON,
    ALLOW_PAGE_LOCKS = ON
    ) ;
GO

E. Disable an index

The following example disables a nonclustered index on the Employee table in the AdventureWorks2022 database.

ALTER INDEX IX_Employee_ManagerID ON HumanResources.Employee DISABLE;

F. Disable constraints

The following example disables a PRIMARY KEY constraint by disabling the PRIMARY KEY index in the AdventureWorks2022 database. The FOREIGN KEY constraint on the underlying table is automatically disabled and warning message is displayed.

ALTER INDEX PK_Department_DepartmentID ON HumanResources.Department DISABLE;

The result set returns this warning message.

Warning: Foreign key 'FK_EmployeeDepartmentHistory_Department_DepartmentID'
on table 'EmployeeDepartmentHistory' referencing table 'Department'
was disabled as a result of disabling the index 'PK_Department_DepartmentID'.

G. Enable constraints

The following example enables the PRIMARY KEY and FOREIGN KEY constraints that were disabled in Example F.

The PRIMARY KEY constraint is enabled by rebuilding the PRIMARY KEY index.

ALTER INDEX PK_Department_DepartmentID ON HumanResources.Department REBUILD;

The FOREIGN KEY constraint is then enabled.

ALTER TABLE HumanResources.EmployeeDepartmentHistory
CHECK CONSTRAINT FK_EmployeeDepartmentHistory_Department_DepartmentID;
GO

H. Rebuild a partitioned index

The following example rebuilds a single partition, partition number 5, of the partitioned index IX_TransactionHistory_TransactionDate in the AdventureWorks2022 database. Partition 5 is rebuilt with ONLINE=ON and the 10 minutes wait time for the low priority lock applies separately to every lock acquired by index rebuild operation. If during this time the lock can't be obtained to complete index rebuild, the rebuild operation statement itself is aborted, due to ABORT_AFTER_WAIT = SELF.

Applies to: SQL Server 2014 (12.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

-- Verify the partitioned indexes.
SELECT *
FROM sys.dm_db_index_physical_stats (DB_ID(),OBJECT_ID(N'Production.TransactionHistory'), NULL , NULL, NULL);
GO
--Rebuild only partition 5.
ALTER INDEX IX_TransactionHistory_TransactionDate
ON Production.TransactionHistory
REBUILD Partition = 5
   WITH (ONLINE = ON (WAIT_AT_LOW_PRIORITY (MAX_DURATION = 10 minutes, ABORT_AFTER_WAIT = SELF)));
GO

I. Change the compression setting of an index

The following example rebuilds an index on a nonpartitioned rowstore table.

ALTER INDEX IX_INDEX1
ON T1
REBUILD
WITH (DATA_COMPRESSION = PAGE);
GO

J. Change the setting of an index with XML compression

Applies to: SQL Server 2022 (16.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance.

The following example rebuilds an index on a nonpartitioned rowstore table.

ALTER INDEX IX_INDEX1
ON T1
REBUILD
WITH (XML_COMPRESSION = ON);
GO

For more data compression examples, see Data compression.

K. Online resumable index rebuild

Applies to: SQL Server 2017 (14.x) and later versions, Azure SQL Database, and Azure SQL Managed Instance

The following examples show how to use online resumable index rebuild.

Execute an online index rebuild as resumable operation with MAXDOP = 1. Executing the same command again after an index operation was paused, automatically resumes the index rebuild operation.

ALTER INDEX test_idx on test_table REBUILD WITH (ONLINE = ON, MAXDOP = 1, RESUMABLE = ON);

Execute an online index rebuild as resumable operation with MAX_DURATION set to 240 minutes.

ALTER INDEX test_idx on test_table REBUILD WITH (ONLINE = ON, RESUMABLE = ON, MAX_DURATION = 240);

Pause a running resumable online index rebuild.

ALTER INDEX test_idx on test_table PAUSE;

Resume an online index rebuild for an index rebuild that was executed as resumable operation specifying a new value for MAXDOP set to 4.

ALTER INDEX test_idx on test_table RESUME WITH (MAXDOP = 4);

Resume an online index rebuild operation for an index online rebuild that was executed as resumable. Set MAXDOP to 2, set the execution time for the index being running as resumable to 240 minutes, and if an index is being blocked on the lock, wait 10 minutes and after that kill all blockers.

ALTER INDEX test_idx on test_table
    RESUME WITH (MAXDOP = 2, MAX_DURATION = 240 MINUTES,
    WAIT_AT_LOW_PRIORITY (MAX_DURATION = 10, ABORT_AFTER_WAIT = BLOCKERS));

Abort resumable index rebuild operation that is running or paused.

ALTER INDEX test_idx on test_table ABORT;

Delen via

ALTER INDEX (Transact-SQL)

Syntax

Arguments

index_name

ALL

database_name

schema_name

table_or_view_name

REBUILD [ WITH ( <rebuild_index_option> [ ,... n ] ) ]

PARTITION

DISABLE

REORGANIZE a rowstore index

REORGANIZE WITH ( LOB_COMPACTION = { ON | OFF } )

REORGANIZE a columnstore index

REORGANIZE WITH ( COMPRESS_ALL_ROW_GROUPS = { ON | OFF } )

SET ( <set_index option> [ ,... n ] )

PAD_INDEX = { ON | OFF }

FILLFACTOR = fillfactor

SORT_IN_TEMPDB = { ON | OFF }

IGNORE_DUP_KEY = { ON | OFF }

STATISTICS_NORECOMPUTE = { ON | OFF }

STATISTICS_INCREMENTAL = { ON | OFF }

ONLINE = { ON | OFF }

RESUMABLE = { ON | OFF}

MAX_DURATION = time [ MINUTES ] used with RESUMABLE = ON (requires ONLINE = ON)

ALLOW_ROW_LOCKS = { ON | OFF }

ALLOW_PAGE_LOCKS = { ON | OFF }

OPTIMIZE_FOR_SEQUENTIAL_KEY = { ON | OFF }

MAXDOP = max_degree_of_parallelism

COMPRESSION_DELAY = { 0 | duration [ minutes ] }

DATA_COMPRESSION

XML_COMPRESSION

ON PARTITIONS ( { <partition_number_expression> | <range> } [ ,...n ] )

RESUME

PAUSE

ABORT

Remarks

Rebuild indexes

Reorganize indexes

Disable indexes

Set options

Row and page locks options

Online index operations

Resumable index operations

Resources

Current functional limitations

WAIT_AT_LOW_PRIORITY with online index operations

Spatial index restrictions

Data compression

Statistics

Permissions

Version notes

Basic syntax example

Examples: Columnstore indexes

A. REORGANIZE demo

B. Compress CLOSED delta rowgroups into the columnstore

C. Compress all OPEN AND CLOSED delta rowgroups into the columnstore

D. Defragment a columnstore index online

E. Rebuild a clustered columnstore index offline

F. Rebuild a partition of a clustered columnstore index offline

G. Change a clustered columnstore index to use archival compression

Examples: Rowstore indexes

A. Rebuild an index

B. Rebuild all indexes on a table and specify options

C. Reorganize an index with LOB compaction

D. Set options on an index

E. Disable an index

F. Disable constraints

G. Enable constraints

H. Rebuild a partitioned index

I. Change the compression setting of an index

J. Change the setting of an index with XML compression

K. Online resumable index rebuild

Related content

Feedback

Aanvullende resources

MAX_DURATION = time [ MINUTES ] used with `RESUMABLE = ON` (requires `ONLINE = ON`)