# DbMpoolFile::set_pgcookie

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    #include <db_cxx.h>

    int
    DbMpoolFile::set(DBT *pgcookie);

# Description

The DbMpoolFile::set_pgcookie method specifies a byte string that is provided to the functions registered to do input or output processing of the file's pages as they are read from or written to, the backing filesystem store. (See the DbEnv::memp_register documentation for more information.)

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

The DbMpoolFile::set_pgcookie 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_pgcookie will replace the existing information.

The DbMpoolFile::set_pgcookie 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_pgcookie 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_pgcookie 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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