txn_stat(DB_ENV *env, DB_TXN_STAT **statp);
The txn_stat function
creates a statistical structure and copies a pointer to it into a
user-specified memory location.
Statistical structures are created 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
library function 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
The transaction region statistics are stored in a structure of type
DB_TXN_STAT. The following DB_TXN_STAT fields will be filled in:
- DB_LSN st_last_ckp;
- The LSN of the last checkpoint.
- DB_LSN st_pending_ckp;
- The LSN of any checkpoint that is currently in progress. If
st_pending_ckp is the same as st_last_ckp there
is no checkpoint in progress.
- 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 interface).
- u_int32_t st_last_txnid;
- The last transaction ID allocated.
- u_int32_t st_maxtxns;
- The maximum number of active transactions possible.
- 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_regsize;
- The size of the region.
- u_int32_t st_region_wait;
- The number of times that a thread of control was forced to wait before
obtaining the region lock.
- u_int32_t st_region_nowait;
- The number of times that a thread of control was able to obtain
the region lock 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).
- DB_LSN lsn;
- The log sequence number of the transaction-begin record.
The txn_stat function returns a non-zero error value on failure and 0 on success.
The txn_stat function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions.
If a catastrophic error has occurred, the txn_stat function may fail and return
DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail
in the same way.
Copyright Sleepycat Software