Package org.firebirdsql.management

Class FBTableStatisticsManager

  • All Implemented Interfaces:
    java.lang.AutoCloseable
    @Volatile(reason="Experimental")
public final class FBTableStatisticsManager
extends java.lang.Object
implements java.lang.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

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Clears the reference to the connection and clears the cache.
      java.util.Map<java.lang.String,​TableStatistics> getTableStatistics()
      Obtains a snapshot of the table statistics of this connection.
      static FBTableStatisticsManager of​(java.sql.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 Detail

      • of

        public static FBTableStatisticsManager of​(java.sql.Connection connection)
                                   throws java.sql.SQLException
        Creates a table statistics manager for the current connection.
        Parameters:
        connection - Connection to gather statistics on.
        Returns:
        a table statistics manager
        Throws:
        java.sql.SQLException - if connection is closed

      • getTableStatistics

        public java.util.Map<java.lang.String,​TableStatistics> getTableStatistics()
                                                                         throws java.sql.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)
        java.sql.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 java.lang.AutoCloseable