Package org.apache.derby.iapi.db
Class OptimizerTrace
java.lang.Object
org.apache.derby.iapi.db.OptimizerTrace
This class provides static methods for controlling the optimizer tracing in a Derby database.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionstatic String
Get the optimizer trace output for the last optimized query as a String.static OptTrace
Get the current optimizer tracer, if any.static void
setOptimizerTrace
(boolean onOrOff) Turn default optimizer tracing on or off.static void
setOptimizerTracer
(OptTrace tracer) Install an optimizer tracer (to enable tracing) or uninstall the current optimizer tracer (to disable tracing).
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Constructor Details
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OptimizerTrace
public OptimizerTrace()
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Method Details
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setOptimizerTrace
public static void setOptimizerTrace(boolean onOrOff) Turn default optimizer tracing on or off.- Parameters:
onOrOff
- Whether to turn optimizer tracing on (true) or off (false).
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setOptimizerTracer
Install an optimizer tracer (to enable tracing) or uninstall the current optimizer tracer (to disable tracing).- Parameters:
tracer
- Null if tracing is being turned off, otherwise an optimizer tracer
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getOptimizerTracer
Get the current optimizer tracer, if any. -
getOptimizerTraceOutput
Get the optimizer trace output for the last optimized query as a String.- Returns:
- The optimizer trace output for the last optimized query as a String. Null will be returned if optimizer trace output is off or not supported or no trace output was found or an exception occurred.
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