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sys.column_store_dictionaries (Transact-SQL)

Contains a row for each dictionary used in xVelocity memory optimized columnstore indexes. Dictionaries are used to encode some, but not all data types, therefore not all columns in a columnstore index have dictionaries. A dictionary can exist as a primary dictionary (for all segments) and possibly for other secondary dictionaries used for a subset of the column's segments.

Column name

Data type

Description

hobt_id

bigint

ID of the heap or B-tree index (hobt) for the table that has this columnstore index.

column_id

int

ID of the columnstore column.

dictionary_id

int

Id of the dictionary.

version

int

Version of the dictionary format.

type

int

Dictionary type:

1 – Hash dictionary containing int values

2 – Not used

3 – Hash dictionary containing string values

4 – Hash dictionary containing float values

For more information about dictionaries, see Columnstore Indexes.

last_id

int

The last data id in the dictionary.

entry_count

bigint

Number of entries in the dictionary.

on_disc_size

bigint

Size of dictionary in bytes.

partition_id

bigint

Indicates the partition ID. Is unique within a database.

Permissions

All columns require at least VIEW DEFINITION permission on the table. The following columns return null unless the user also has SELECT permission: last_id, entry_count, data_ptr.

The visibility of the metadata in catalog views is limited to securables that a user either owns or on which the user has been granted some permission. For more information, see Metadata Visibility Configuration.

See Also

Reference

Object Catalog Views (Transact-SQL)

Catalog Views (Transact-SQL)

sys.columns (Transact-SQL)

sys.all_columns (Transact-SQL)

sys.computed_columns (Transact-SQL)

sys.column_store_segments (Transact-SQL)

Concepts

Querying the SQL Server System Catalog FAQ

Columnstore Indexes

Columnstore Indexes