# PerformanceInsightsMetricDimensionGroup
A logical grouping of Performance Insights metrics for a related subject area. For example, the `db.sql` dimension group consists of the following dimensions:
+ `db.sql.id` - The hash of a running SQL statement, generated by Performance Insights.
+ `db.sql.db_id` - Either the SQL ID generated by the database engine, or a value generated by Performance Insights that begins with `pi-`.
+ `db.sql.statement` - The full text of the SQL statement that is running, for example, `SELECT * FROM employees`.
+ `db.sql_tokenized.id` - The hash of the SQL digest generated by Performance Insights.
**Note**
Each response element returns a maximum of 500 bytes. For larger elements, such as SQL statements, only the first 500 bytes are returned.
## Contents
**Note**
In the following list, the required parameters are described first.
** Dimensions.member.N **
A list of specific dimensions from a dimension group. If this list isn't included, then all of the dimensions in the group were requested, or are present in the response.
Type: Array of strings
Required: No
** Group **
The available dimension groups for Performance Insights metric type.
Type: String
Required: No
** Limit **
The maximum number of items to fetch for this dimension group.
Type: Integer
Required: No
## See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following:
+ [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/rds-2014-10-31/PerformanceInsightsMetricDimensionGroup)
+ [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/rds-2014-10-31/PerformanceInsightsMetricDimensionGroup)
+ [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/rds-2014-10-31/PerformanceInsightsMetricDimensionGroup)