9.15. Starburst SQL Server Connector#

The Starburst SQL Server Connector is an extended version of the SQL Server Connector with configuration and usage identical.

The following improvements are included:

User Impersonation#

The SQL Server connector supports user impersonation.

User impersonation can be enabled in the catalog file:

sqlserver.impersonation.enabled=true

User impersonation in SQL Server connector is based on EXECUTE AS USER. For more details visit: docs.microsoft.com.

Table Statistics#

SQL Server connector supports table and column statistics, as documented in Table Statistics. The statistics are collected by SQL Server and retrieved by the connector. Currently, the connector can use information stored in single-column statistics. SQL Server Database can automatically create column statistics for certain columns. If column statistics were not created automatically for a certain column, you can create them by executing the following statement in SQL Server Database.

CREATE STATISTICS my_statistics_name ON table_schema.table_name (column_name);

SQL Server Database routinely updates the statistics. In some cases, you may want to force statistics update (e.g. after defining new column statistics or after changing data in the table). You can do that by executing the following statement in SQL Server Database.

UPDATE STATISTICS table_schema.table_name;

Refer to SQL Server documentation for information about options, limitations and additional considerations.

The table and column statistics can be viewed in Presto using SHOW STATS and are used for Cost based optimizations.

Table Statistics Configuration Properties#
Property Name Description Default
statistics.enabled Enables table and column statistics. true
statistics.cache-ttl Duration for which table and column statistics are cached. 0s
statistics.cache-missing Cache the fact that table statistics are not available. false