Enable or Disable Index Statistics Collection Error Messages
On databases that do not support statistics, you can specify if Hyper-Q should return an error when attempting to collect or drop statistics, or ignore the error.
If enabled, Hyper-Q reports errors if it fails to either collect or drop statistics. In the following example a COLLECT STATISTICS statement and a DROP STATISTICS statement return the following errors when allow_stats_commands is set to true.
COLLECT STATISTICS COLUMN column_name ON table_name; *** Failure 3706 DTM9074: Unsupported Collect Statistics ('bigquery-010000-core-serializer':678) DROP STATISTICS COLUMN column_name ON table_name; *** Failure 3706 DTM9223: Unsupported Drop Statistics ('bigquery-010000-core-serializer':681)
You can configure Hyper-Q to ignore these errors and not report them.
The syntax for allow_stats_commands is:
allow_stats_commands = true | false
where:
Parameter | Description |
|---|---|
| Hyper-Q reports errors when it encounters a database that does not support statistics collection. |
| Hyper-Q ignores errors when either a COLLECT STATISTICS statement or a DROP STATISTICS statement is issued against a database that does not support statistics collection. On BigQuery, this is the default behavior. |
Hint Scope
The allow_stats_commands hint can be specified at the statement, request, session, and application level. To learn more about Hyper-Q SQL hints, and how to use them within a SQL query, see About Hyper-Q SQL Hints.
You can specify allow_stats_commands as an application level (or global) setting in the Hyper-Q configuration file (dtm.ini). To enable allow_stats_commands, set it to true. The default value is false.
"gateway".allow_stats_commands=true
If set to true, Hyper-Q reports errors if it fails to collect or drop statistics. In the following example a COLLECT STATISTICS statement and a DROP STATISTICS statement return the following errors when allow_stats_commands is set to true.
COLLECT STATISTICS COLUMN column_name ON table_name; *** Failure 3706 DTM9074: Unsupported Collect Statistics ('bigquery-010000-core-serializer':678) DROP STATISTICS COLUMN column_name ON table_name; *** Failure 3706 DTM9223: Unsupported Drop Statistics ('bigquery-010000-core-serializer':681)
To learn more about specifying a hint as a gateway option in the Hyper-Q configuration file, see Gateway Configuration Parameters.
You can specify allow_stats_commands as a query hint. This example specifies the hint within COLLECT STATISTICS and DROP STATISTICS statements, and disables error reporting for databases that do not support statistics collection.
COLLECT --@dtm_stats_commands=false STATISTICS COLUMN column_name ON table_name; DROP --@dtm_allow_stats_commands=false STATISTICS COLUMN column_name ON table_name;
To learn more about Hyper-Q SQL hints, and how to use them within a SQL query, see About Hyper-Q SQL Hints.