QUERYBUFFERSTATS System Table Description
Description
A pseudo table generated to show queries that have used significant amounts of memory.
This is currently limited to sorting operations (those running queries that use the ORDER BY clause).
Support for additional operations will be added in future releases of NuoDB.
By default, the ten queries with the highest memory usage in compatible processing modules are stored in the QUERYBUFFERSTATS table.
The number of queries listed is configurable using the MAX_QUERY_COUNT system property.
For more information on using MAX_QUERY_COUNT, see SQL System Properties.
Fields
| Field | Type | Description | ||||||
|---|---|---|---|---|---|---|---|---|
SQLSTRING |
string |
The SQL statement requiring memory when executed. |
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USER |
string |
The SQL user for the database connection. |
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SCHEMA |
string |
The current SQL schema for the connection at the time of invocation of the query. |
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PARAMS |
string |
A string representing parameters specified in the query. The string representing each parameter is of the format:
Where:
Each parameter string is separated by a space. For example:
|
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NODEID |
bigint |
A unique identifier specifying which Transaction Engine (TE) the query’s client was connected to. |
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DATA_BUFFERING_MB |
bigint |
The peak amount of memory buffering required to process this query. For more information, refer to |
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TIMESTAMP |
string |
The timestamp for when the query began. |