# DbEnv::set_tmp_dir

`

###

    #include <db_cxx.h>

    int
    DbEnv::set_tmp_dir(const char *dir);

# Description

The path of a directory to be used as the location of temporary files. The files created to back in-memory access method databases will be created relative to this path. These temporary files can be quite large, depending on the size of the database.

If no directories are specified, the following alternatives are checked in the specified order. The first existing directory path is used for all temporary files.

1. The value of the environment variable TMPDIR.
2. The value of the environment variable TEMP.
3. The value of the environment variable TMP.
4. The value of the environment variable TempFolder.
5. The value returned by the GetTempPath interface.
6. The directory /var/tmp.
7. The directory /usr/tmp.
8. The directory /temp.
9. The directory /tmp.
10. The directory C:/temp.
11. The directory C:/tmp.

Note: environment variables are only checked if one of the DB_USE_ENVIRON or DB_USE_ENVIRON_ROOT flags were specified.

Note: the GetTempPath interface is only checked on Win/32 platforms.

The DbEnv::set_tmp_dir method configures operations performed using the specified DbEnv handle, not all operations performed on the underlying database environment.

The DbEnv::set_tmp_dir interface may not be called after the DbEnv::open interface is called. If the database environment already exists when DbEnv::open is called, the information specified to DbEnv::set_tmp_dir must be consistent with the existing environment or corruption can occur.

The DbEnv::set_tmp_dir 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.

The database environment's temporary file directory may also be set using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_tmp_dir", one or more whitespace characters, and the directory name. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

# Errors

The DbEnv::set_tmp_dir method may fail and throw an exception or return a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  Called after DbEnv::open was called.

The DbEnv::set_tmp_dir 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 DbEnv::set_tmp_dir 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

# See Also

Database Environments and Related Methods`

Copyright Sleepycat Software