Module org.firebirdsql.jaybird

Package org.firebirdsql.management

Class FBTableStatisticsManager

java.lang.Object

org.firebirdsql.management.FBTableStatisticsManager

All Implemented Interfaces:

AutoCloseable

@Volatile(reason="Experimental")
public final class FBTableStatisticsManager
extends Object
implements AutoCloseable

Provides access to the table statistics of a Connection.

The table statistics are execution statistics of the specific connection, and are not global statistics.

This manager retains a reference to underlying FbDatabase instance and holds a cache of table names. Closing this manager will remove the reference the database handle (but not close it!) and releases the cache.

This class is not thread-safe (though its use of the underlying connection is thread-safe).

Since:

5

Author:

Mark Rotteveel

Method Summary

Modifier and Type	Method	Description
void	close()	Clears the reference to the connection and clears the cache.
Map<String,TableStatistics>	getTableStatistics()	Obtains a snapshot of the table statistics of this connection.
static FBTableStatisticsManager	of(Connection connection)	Creates a table statistics manager for the current connection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

of

public static FBTableStatisticsManager of(Connection connection)
                                   throws SQLException

Creates a table statistics manager for the current connection.

Parameters:

connection - Connection to gather statistics on.

Returns:

a table statistics manager

Throws:

SQLException - if connection is closed

getTableStatistics

public Map<String,TableStatistics> getTableStatistics()
                                               throws SQLException

Obtains a snapshot of the table statistics of this connection.

A table is only present in the map if this connection touched it in a way which generated a statistic.

Returns:

map from table name to table statistics

Throws:

InfoTruncatedException - if a truncated response is received, after retrying 3 times (total: 4 attempts) while increasing the buffer size; it is possible that subsequent calls to this method may recover (as that will increase the buffer size even more)

SQLException - if the connection is closed, or if obtaining the statistics failed due to a database access error

close

public void close()

Clears the reference to the connection and clears the cache.

This method does not close the connection wrapped by this manager.

Closing a table statistics manager is not required. It can be used to clean up early, or to prevent a user of this class from gathering further statistics.

Specified by:

close in interface AutoCloseable