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DB_TXN->commit
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#include <db.h>
int
DB_TXN->commit(DB_TXN *tid, u_int32_t flags);
Description
The DB_TXN->commit method ends the transaction.
In the case of nested transactions, if the transaction is a parent
transaction, committing the parent transaction causes all unresolved
children of the parent to be committed. In the case of nested
transactions, if the transaction is a child transaction, its locks are
not released, but are acquired by its parent. Although the commit of the
child transaction will succeed, the actual resolution of the child
transaction is postponed until the parent transaction is committed or
aborted; that is, if its parent transaction commits, it will be
committed; and if its parent transaction aborts, it will be aborted.
The flags value must be set to 0 or
one of the following values:
- DB_TXN_NOSYNC
- Do not synchronously flush the log. This means the transaction will
exhibit the ACI (atomicity, consistency, and isolation) properties, but
not D (durability); that is, database integrity will be maintained, but
it is possible that this transaction may be undone during recovery.
This behavior may be set for a Berkeley DB environment using the
DB_ENV->set_flags interface or for a single transaction using the
DB_ENV->txn_begin interface. Any value specified in this interface
overrides both of those settings.
- DB_TXN_SYNC
- Synchronously flush the log. This means the transaction will exhibit
all of the ACID (atomicity, consistency, isolation, and durability)
properties.
This behavior is the default for Berkeley DB environments unless the
DB_TXN_NOSYNC flag was specified to the DB_ENV->set_flags
interface. This behavior may also be set for a single transaction using
the DB_ENV->txn_begin interface. Any value specified in this interface
overrides both of those settings.
All cursors opened within the transaction must be closed before the
transaction is committed.
After DB_TXN->commit has been called, regardless of its return, the
DB_TXN handle may not be accessed again. If DB_TXN->commit
encounters an error, the transaction and all child transactions of the
transaction are aborted.
The DB_TXN->commit method returns a non-zero error value on failure and 0 on success.
Errors
The DB_TXN->commit method 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 DB_TXN->commit method may fail and
return DB_RUNRECOVERY,
in which case all subsequent Berkeley DB calls will fail in the same way.
Class
DB_ENV, DB_TXN
See Also
Transaction Subsystem and Related Methods
Copyright Sleepycat Software
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