# DbEnv.log_put

`

###

    import com.sleepycat.db.*;

    public void log_put(DbLsn lsn, Dbt data, int flags)
    	throws DbException;

# Description

The DbEnv.log_put method appends records to the log. The DbLsn of the put record is returned in the lsn argument. The flags argument may be set to one of the following values:

Db.DB_CHECKPOINT
  The log should write a checkpoint record, recording any information necessary to make the log structures recoverable after a crash.

Db.DB_CURLSN
  The DbLsn of the next record to be put is returned in the lsn argument.

Db.DB_FLUSH
  The log is forced to disk after this record is written, guaranteeing that all records with DbLsn values less than or equal to the one being put are on disk before this function returns (this function is most often used for a transaction commit, see DbTxn.commit for more information).

  The caller is responsible for providing any necessary structure to data. (For example, in a write-ahead logging protocol, the application must understand what part of data is an operation code, what part is redo information, and what part is undo information. In addition, most transaction managers will store in data the DbLsn of the previous log record for the same transaction, to support chaining back through the transaction's log records during undo.)

The DbEnv.log_put method throws an exception that encapsulates a non-zero error value on failure.

# Errors

The DbEnv.log_flush method may fail and throw an exception encapsulating a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  The record to be logged is larger than the maximum log record.

The DbEnv.log_put method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the DbEnv.log_put method may fail and throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

### Class

DbEnv

# See Also

DbEnv.set_lg_bsize, DbEnv.set_lg_max, DbEnv.log_archive, DbEnv.log_compare, DbEnv.log_file, DbEnv.log_flush, DbEnv.log_get, DbEnv.log_put, DbEnv.log_register, DbEnv.log_stat and DbEnv.log_unregister.`

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