Library Version 18.1.40

DB_MPOOLFILE->set_priority()
Prev | Chapter 8. The DB_MPOOLFILE Handle | Next

## DB_MPOOLFILE->set_priority()

    #include <db.h>

    int
    DB_MPOOLFILE->set_priority(DB_MPOOLFILE *mpf, DB_CACHE_PRIORITY priority);

Set the cache priority for pages referenced by the DB_MPOOLFILE handle.

The priority of a page biases the replacement algorithm to be more or less likely to discard a page when space is needed in the cache. The bias is temporary, and pages will eventually be discarded if they are not referenced again. The `DB_MPOOLFILE->set_priority()` method is only advisory, and does not guarantee pages will be treated in a specific way.

To set the priority for the pages belonging to a particular database, call the `DB_MPOOLFILE->set_priority()` method using the DB_MPOOLFILE handle returned by the DB->get_mpf() method.

The `DB_MPOOLFILE->set_priority()` method configures a file in the cache, not only operations performed using the specified DB_MPOOLFILE handle.

The `DB_MPOOLFILE->set_priority()` method may be called at any time during the life of the application.

The `DB_MPOOLFILE->set_priority()` method returns a non-zero error value on failure and 0 on success.

### Parameters

#### priority

The priority parameter must be set to one of the following values:

- `DB_PRIORITY_VERY_LOW`

  The lowest priority: pages are the most likely to be discarded.

- `DB_PRIORITY_LOW`

  The next lowest priority.

- `DB_PRIORITY_DEFAULT`

  The default priority.

- `DB_PRIORITY_HIGH`

  The next highest priority.

- `DB_PRIORITY_VERY_HIGH`

  The highest priority: pages are the least likely to be discarded.

### Class

DB_ENV, DB_MPOOLFILE

### See Also

Memory Pools and Related Methods

Prev | Up | Next
DB_MPOOLFILE->set_pgcookie() | Home | Chapter 9. Mutex Methods