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DbEnv.txn_stat

APIRef

import com.sleepycat.db.*;

public DbTxnStat txn_stat(int flags) throws DbException;

Description

The DbEnv.txn_stat method returns the transaction subsystem statistics.

The flags value must be set to 0 or the following value:

Db.DB_STAT_CLEAR
Reset statistics after returning their values.

The DbEnv.txn_stat method creates a DbTxnStat object encapsulating the transaction region statistics. The following data fields are available from the DbTxnStat object:

public DbLsn st_last_ckp;
The LSN of the last checkpoint.
public long st_time_ckp;
The time the last completed checkpoint finished (as the number of seconds since the Epoch, returned by the IEEE/ANSI Std 1003.1 (POSIX) time interface).
public int st_last_txnid;
The last transaction ID allocated.
public int st_maxtxns;
The maximum number of active transactions possible.
public int st_nactive;
The number of transactions that are currently active.
public int st_maxnactive;
The maximum number of active transactions at any one time.
public int st_nbegins;
The number of transactions that have begun.
public int st_naborts;
The number of transactions that have aborted.
public int st_ncommits;
The number of transactions that have committed.
public int st_nrestores;
The number of transactions that have been restored.
public int st_regsize;
The size of the region.
public int st_region_wait;
The number of times that a thread of control was forced to wait before obtaining the region lock.
public int st_region_nowait;
The number of times that a thread of control was able to obtain the region lock without waiting.
public Active st_txnarray[];
The array of active transactions. Each element of the array is an object of type DbTxnStat.Active, a top level inner class, that has the following fields:

public int txnid;
The transaction ID of the transaction.
public int parentid;
The transaction ID of the parent transaction (or 0, if no parent).
public DbLsn lsn;
The current log sequence number when the transaction was begun.

The DbEnv.txn_stat method throws an exception that encapsulates a non-zero error value on failure.

Errors

The DbEnv.txn_stat method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the DbEnv.txn_stat method may fail and throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

Class

DbEnv, DbTxn

See Also

Transaction Subsystem and Related Methods

APIRef

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