Limitations for Stretch Database

THIS TOPIC APPLIES TO: yesSQL Server (starting with 2016)noAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

Learn about limitations for Stretch-enabled tables, and about limitations that currently prevent you from enabling Stretch for a table.

Limitations for Stretch-enabled tables

Stretch-enabled tables have the following limitations.

Constraints

  • Uniqueness is not enforced for UNIQUE constraints and PRIMARY KEY constraints in the Azure table that contains the migrated data.

DML operations

  • You can't UPDATE or DELETE rows that have been migrated, or rows that are eligible for migration, in a Stretch-enabled table or in a view that includes Stretch-enabled tables.

  • You can't INSERT rows into a Stretch-enabled table on a linked server.

Indexes

  • You can't create an index for a view that includes Stretch-enabled tables.

  • Filters on SQL Server indexes are not propagated to the remote table.

Limitations that currently prevent you from enabling Stretch for a table

The following items currently prevent you from enabling Stretch for a table.

Table properties

  • Tables that have more than 1,023 columns or more than 998 indexes

  • FileTables or tables that contain FILESTREAM data

  • Tables that are replicated, or that are actively using Change Tracking or Change Data Capture

  • Memory-optimized tables

Data types

  • text, ntext and image

  • timestamp

  • sql_variant

  • XML

  • CLR data types including geometry, geography, hierarchyid, and CLR user-defined types

    Column types

    • COLUMN_SET
  • Computed columns

Constraints

  • Default constraints and check constraints

  • Foreign key constraints that reference the table. In a parent-child relationship (for example, Order and Order_Detail), you can enable Stretch for the child table (Order_Detail) but not for the parent table (Order).

Indexes

  • Full text indexes

  • XML indexes

  • Spatial indexes

  • Indexed views that reference the table

See Also

Identify databases and tables for Stretch Database by running Stretch Database Advisor
Enable Stretch Database for a database
Enable Stretch Database for a table