Berkeley DB: DbEnv::set_mp_max_openfd
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++

DbEnv::set_mp_max_openfd |

`

    #include <db_cxx.h>

    int
    DbEnv::set_mp_max_openfd(int maxopenfd);

    int
    DbEnv::get_mp_max_openfd(int *maxopenfdp);

Description: DbEnv::set_mp_max_openfd

The DbEnv::set_mp_max_openfd method limits the number of file descriptors the library will open concurrently when flushing dirty pages from the cache.

The database environment's limit on open file descriptors to flush dirty pages may also be configured using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_max_openfd", one or more whitespace characters, and the number of open file descriptors. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

The DbEnv::set_mp_max_write method configures a database environment, not only operations performed using the specified DbEnv handle.

The DbEnv::set_mp_max_openfd 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.

Parameters
maxopenfd

- The maximum number of file descriptors that may be concurrently opened by the library when flushing dirty pages from the cache.

Errors

The DbEnv::set_mp_max_openfd method may fail and throw DbException, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

EINVAL

- An invalid flag value or parameter was specified.

Description: DbEnv::get_mp_max_openfd

The DbEnv::get_mp_max_openfd method returns the maximum number of file descriptors open.

The DbEnv::get_mp_max_openfd method may be called at any time during the life of the application.

The DbEnv::get_mp_max_openfd 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.

Parameters
maxopenfdp

- The DbEnv::get_mp_max_openfd method returns the maximum number of file descriptors open in maxopenfdp.

Class DbEnv, DbMpoolFile
See Also Memory Pools and Related Methods`

Copyright (c) 1996,2008 Oracle. All rights reserved.