Library Version 18.1.40

DbEnv::set_ext_file_threshold()
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## DbEnv::set_ext_file_threshold()

    #include <db_cxx.h>

    int
    DbEnv::set_ext_file_threshold(u_int32_t bytes, u_int32_t flags);

The `DbEnv::set_ext_file_threshold()` method sets a default size for the environment which is used to determine when a data item will be stored as an external file. Data items sized less than this threshold are stored as normal data within the database. Data items larger than this size are stored on-disk in a subdirectory set aside for the purpose.

If this threshold value is set to `0`, then external file support is turned off by default for databases created in the environment. If this method is never called, then the default external file threshold is `0`.

This method only sets the default external file threshold for the environment. The external file threshold can be set for individual databases created within the environment using Db::set_ext_file_threshold() .

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

You may call this method at any time after the DbEnv handle has been created.

Unless otherwise specified, the `DbEnv::set_ext_file_threshold()` 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

#### bytes

The bytes parameter identifies the threshold size, in bytes, beyond which a data item is stored as an external file.

#### flags

The flags parameter must be set to 0.

### Errors

The `DbEnv::set_ext_file_threshold()` method may fail and throw a DbException exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

#### EINVAL

If an invalid flag or parameter was specified.

### Class

DbEnv

### See Also

External Files and Related Methods

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