# DbMpoolFile::set_lsn_offset

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    #include <db_cxx.h>

    int
    DbMpoolFile::set(int32_t lsn_offset);

# Description

The DbMpoolFile::set_lsn_offset method specifies the zero-based byte offset of a log sequence number (DbLsn) on the file's pages, for the purposes of page-flushing as part of transaction checkpoint. (See the DbEnv::memp_sync documentation for more information.)

The DbMpoolFile::set_lsn_offset method configures a file in the memory pool, not only operations performed using the specified DbMpoolFile handle.

The DbMpoolFile::set_lsn_offset interface may not be called after the DbMpoolFile::open interface is called. If the file is already open in the memory pool when DbMpoolFile::open is called, the information specified to DbMpoolFile::set_lsn_offset must be consistent with the existing file or an error will be returned.

The DbMpoolFile::set_lsn_offset 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 DbMpoolFile::set_lsn_offset 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 DbMpoolFile::set_lsn_offset method may fail and either return DB_RUNRECOVERY or throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

# Class

DbEnv, DbMpoolFile

# See Also

Memory Pools and Related Methods`

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