admin_statement
        : SHUTDOWN opt_log
        | CHECKPOINT opt_log
        | BACKUP opt_log
        ;

The checkpoint is a point in the history of a database where all the state is written on disk as a single, consistent image that contains all the state committed so far and no uncommitted state. A transaction log starts after a checkpoint and contains the information to allow the recreation of the effect of transactions committed since the checkpoint. The checkpoint state and the transaction log together allow recovering the database up to the last committed transaction.

The CHECKPOINT statement forces a checkpoint to be made. Making the checkpoint allows starting a new transaction log. If no new log name is specified the old log is truncated to length 0 and reused for logging transactions. If the CheckpointAuditTrail option is enabled in virtuoso.ini a new log will be started even if no new log is specified in the checkpoint or shutdown statement.

The SHUTDOWN statement performs a CHECKPOINT, and terminates the server upon completion.

BACKUP is an alternate notation for backup().

Example 9.38. Examples:

checkpoint 'new.log';
backup 'bak.log';
shutdown 'new2.log';

The above sequence of commands makes a checkpoint and starts logging subsequent transactions into new.log. The backup statement makes bak.log, which represents the state prior to starting new.log. The shutdown statement makes a new checkpoint and marks new2.log as the log file to be used for logging transactions after the database restarts. The database server exits at the completion of the SHUTDOWN statement.

replay ('bak.log');
replay ('new.log');

These statements executed on an empty database will recreate the state in effect after the last transaction to commit before the SHUTDOWN statement of the previous example.

[Tip] See Also

The Backup section for more backup and recovery information.

Example 9.39. Example for control the transaction logging:

create procedure log_test ()
{
  -- disable the transaction logging
  log_enable (0);

  -- action code, for ex.:
  delete from TAG_REL_INX;
  insert into TAG_REL_INX (TR_T1, TR_T2, TR_COUNT) select TR_T1, TR_T2, TR_COUNT from TAG_REL;

  exec('checkpoint');

  -- enable the transaction logging
  log_enable (1);
};