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DB_ENV->txn_stat

API Ref

#include <db.h>

int DB_ENV->txn_stat(DB_ENV *env, DB_TXN_STAT **statp, u_int32_t flags);

int DB_ENV->txn_stat_print(DB_ENV *env, u_int32_t flags);


Description: DB_ENV->txn_stat

The DB_ENV->txn_stat method returns the transaction subsystem statistics.

The DB_ENV->txn_stat method creates a statistical structure of type DB_TXN_STAT and copies a pointer to it into a user-specified memory location.

Statistical structures are stored in allocated memory. If application-specific allocation routines have been declared (see DB_ENV->set_alloc for more information), they are used to allocate the memory; otherwise, the standard C library malloc(3) is used. The caller is responsible for deallocating the memory. To deallocate the memory, free the memory reference; references inside the returned memory need not be individually freed.

The following DB_TXN_STAT fields will be filled in:

DbLsn st_last_ckp;
The LSN of the last checkpoint.
time_t 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 function).
u_int32_t st_last_txnid;
The last transaction ID allocated.
u_int32_t st_maxtxns;
The maximum number of active transactions configured.
u_int32_t st_nactive;
The number of transactions that are currently active.
u_int32_t st_maxnactive;
The maximum number of active transactions at any one time.
u_int32_t st_nbegins;
The number of transactions that have begun.
u_int32_t st_naborts;
The number of transactions that have aborted.
u_int32_t st_ncommits;
The number of transactions that have committed.
u_int32_t st_nrestores;
The number of transactions that have been restored.
roff_t st_regsize;
The size of the transaction region, in bytes.
u_int32_t st_region_wait;
The number of times that a thread of control was forced to wait before obtaining the transaction region mutex.
u_int32_t st_region_nowait;
The number of times that a thread of control was able to obtain the transaction region mutex without waiting.
DB_TXN_ACTIVE *st_txnarray;
A pointer to an array of st_nactive DB_TXN_ACTIVE structures, describing the currently active transactions. The following fields of the DB_TXN_ACTIVE structure will be filled in:
u_int32_t txnid;
The transaction ID of the transaction.
u_int32_t parentid;
The transaction ID of the parent transaction (or 0, if no parent).
uintmax_t thread_id;
The thread of control ID of the originator of the transaction.
DbLsn lsn;
The current log sequence number when the transaction was begun.
u_int32_t xa_status;
If the transaction is an XA transaction, the status of the transaction, otherwise 0.
u_int8_t xid[DB_XIDDATASIZE];
If the transaction is an XA transaction, the transaction's XA ID.
char name[];
If a name was specified for the transaction, up to the first 50 bytes of that name, followed by a nul termination byte.

The DB_ENV->txn_stat method returns a non-zero error value on failure and 0 on success.

Parameters

flags
The flags parameter must be set to 0 or the following value:
DB_STAT_CLEAR
Reset statistics after returning their values.
statp
The statp parameter references memory into which a pointer to the allocated statistics structure is copied.

Errors

The DB_ENV->txn_stat method may fail and return one of the following non-zero errors:

EINVAL
An invalid flag value or parameter was specified.

Description: DB_ENV->txn_stat_print

The DB_ENV->txn_stat_print method displays the transaction subsystem statistical information, as described for the DB_ENV->txn_stat method. The information is printed to a specified output channel (see the DB_ENV->set_msgfile method for more information), or passed to an application callback function (see the DB_ENV->set_msgcall method for more information).

The DB_ENV->txn_stat_print method may not be called before the DB_ENV->open method has been called.

The DB_ENV->txn_stat_print method returns a non-zero error value on failure and 0 on success.

Parameters

flags
The flags parameter must be set to 0 or the following value:
DB_STAT_ALL
Display all available information.

Class

DB_ENV, DB_TXN

See Also

Transaction Subsystem and Related Methods

APIRef

Copyright (c) 1996-2005 Sleepycat Software, Inc. - All rights reserved.