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DbEnv::txn_recover
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#include <db_cxx.h>
int
DbEnv::txn_recover(DB_PREPLIST preplist[],
long count, long *retp, u_int32_t flags);
Description
The DbEnv::txn_recover interface returns a list of prepared but not
yet resolved transactions. The DbEnv::txn_recover method should only be
called after the environment has been recovered. Because database
environment state must be preserved between recovery and the application
calling DbEnv::txn_recover, applications must either call
DbEnv::txn_recover using the same environment handle used when recovery
is done, or the database environment must not be configured using the
DB_PRIVATE flag.
On return from DbEnv::txn_recover, the preplist argument will
be filled in with a list of transactions that must be resolved by the
application (committed, aborted or discarded). The preplist
argument is a structure of type DB_PREPLIST; the following DB_PREPLIST
fields will be filled in:
- DB_TXN *txn;
- The transaction handle for the transaction.
- u_int8_t gid[DB_XIDDATASIZE];
- The global transaction ID for the transaction. The global transaction
ID is the one specified when the transaction was prepared. The
application is responsible for ensuring uniqueness among global
transaction IDs.
The application must call DbTxn::abort, DbTxn::commit or
DbTxn::discard on each returned DbTxn handle before
starting any new operations.
The count parameter specifies the number of available entries
in the passed-in preplist array. The retp parameter
returns the number of entries DbEnv::txn_recover has filled in, in the
array.
The flags value must be set to one of the following values:
- DB_FIRST
- Begin returning a list of prepared, but not yet resolved transactions.
- DB_NEXT
- Continue returning a list of prepared, but not yet resolved transactions,
starting where the last call to DbEnv::txn_recover left off.
The DbEnv::txn_recover method either returns a non-zero error value or throws an exception that
encapsulates a non-zero error value on failure, and returns 0 on success.
Errors
The DbEnv::txn_recover method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv::txn_recover method may fail and either
return DB_RUNRECOVERY or throw an exception encapsulating
DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail
in the same way.
Class
DbEnv, DbTxn
See Also
DbEnv::set_tx_max,
DbEnv::set_tx_recover,
DbEnv::set_tx_timestamp,
DbTxn::abort,
DbEnv::txn_begin,
DbEnv::txn_checkpoint,
DbTxn::commit,
DbTxn::discard,
DbTxn::id,
DbTxn::prepare,
DbEnv::txn_recover,
DbTxn::set_timeout
and
DbEnv::txn_stat.
Copyright Sleepycat Software
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