SYSCS_DIAG.STATEMENT_DURATION diagnostic table function

You can use the SYSCS_DIAG.STATEMENT_DURATION diagnostic table function to analyze the execution duration of the useful SQL statements in the derby.log file or a log file that you specify.

You can also use this diagnostic table function to get an indication of where the bottlenecks are in the JDBC code for an application.

For a database for which authentication and SQL authorization are both enabled, only the database owner can access this diagnostic table function. See "Configuring user authentication" and "Configuring user authorization" in the Derby Security Guide for more information.

To access the SYSCS_DIAG.STATEMENT_DURATION diagnostic table function, you must use the SQL table function syntax.

For example:

SELECT * 
    FROM TABLE (SYSCS_DIAG.STATEMENT_DURATION()) 
    AS T1

where T1 is a user-specified table name that is any valid identifier.

Restriction: For each transaction ID, a row is not returned for the last statement with that transaction ID. Transaction IDs change within a connection after a commit or rollback, if the transaction that just ended modified data.

You can specify a log file name as an optional argument to the SYSCS_DIAG.STATEMENT_DURATION diagnostic table function. When you specify a log file name, the file name must be an expression whose data type maps to a Java string.

For example:

SELECT * 
    FROM TABLE (SYSCS_DIAG.STATEMENT_DURATION('somederby.log')) 
    AS T1

Tip: By default Derby log files contain only boot, shutdown, and error messages. See the derby.stream.error.logSeverityLevel property and the derby.language.logStatementText property for instructions on how to print more information to Derby log files. You can then query that information by using the SYSCS_DIAG.STATEMENT_DURATION diagnostic table function.

The returned table has the columns shown in the following table.

Table 1. Columns returned by the SYSCS_DIAG.STATEMENT_DURATION table function
Column Name	Type	Length	Nullable	Contents
TS	VARCHAR	26	false	The timestamp of the statement.
THREADID	VARCHAR	80	false	The thread name.
XID	VARCHAR	15	false	The transaction ID.
LOGTEXT	LONG VARCHAR	32,700	true	The text of the statement or commit or rollback.
DURATION	VARCHAR	10	false	The duration, in milliseconds, of the statement.