Berkeley DB: DbTxnMgr.checkpoint
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btr ee,hash,hashing,transaction,transactions,locking,logging,access method,access me thods,java,C,C++

# DbTxnMgr.checkpoint

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    import com.sleepycat.db.*;

    int
    public void checkpoint(int kbyte, int min)
    	throws DbException;

# Description

The DbTxnMgr.checkpoint method flushes the underlying memory pool, writes a checkpoint record to the log and then flushes the log.

If either kbyte or min is non-zero, the checkpoint is only done if more than min minutes have passed since the last checkpoint, or if more than kbyte kilobytes of log data have been written since the last checkpoint.

The DbTxnMgr.checkpoint method throws an exception that encapsulates an errno on failure, and DB_INCOMPLETE if there were pages that needed to be written but that DbMpool.sync was unable to write immediately. In this case, the DbTxnMgr.checkpoint call should be retried.

The DbTxnMgr.checkpoint method is the underlying method used by the db_checkpoint utility. See the db_checkpoint utility source code for an example of using DbTxnMgr.checkpoint in a POSIX 1003.1 environment.

# Errors

If a fatal error occurs in Berkeley DB, the DbTxnMgr.checkpoint method may fail and throw a DbRunRecoveryException, at which point all subsequent database calls will also fail in the same way.

The DbTxnMgr.checkpoint method may fail and throw an exception for any of the errors specified for the following Berkeley DB and C library functions: abort(3), fcntl(3), fflush(3), fprintf(3), free(3), getpid(3), DbLog.compare, DbLog.put, malloc(3), memcpy(3), DbMpool.sync, memset(3), strerror(3), time(3), vfprintf(3), and vsnprintf(3).

In addition, the DbTxnMgr.checkpoint method may fail and throw an exception encapsulating errno for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

# Class

DbTxnMgr

# See Also

DbTxnMgr.begin, DbTxnMgr.checkpoint, DbTxnMgr.close, DbTxnMgr.open, DbTxnMgr.stat and DbTxnMgr.unlink.`