Berkeley DB: Db::set_pagesize
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++

### Db::set_pagesize |

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###

    #include <db_cxx.h>

    int
    Db::set_pagesize(u_int32_t pagesize);

    int
    Db::get_pagesize(u_int32_t *pagesizep);

### Description: Db::set_pagesize

Set the size of the pages used to hold items in the database, in bytes. The minimum page size is 512 bytes, the maximum page size is 64K bytes, and the page size must be a power-of-two. If the page size is not explicitly set, one is selected based on the underlying filesystem I/O block size. The automatically selected size has a lower limit of 512 bytes and an upper limit of 16K bytes.

For information on tuning the Berkeley DB page size, see Selecting a page size.

The Db::set_pagesize method configures a database, not only operations performed using the specified Db handle.

The Db::set_pagesize method may not be called after the Db::open method is called. If the database already exists when Db::open is called, the information specified to Db::set_pagesize will be ignored.

If creating additional databases in a single physical file, information specified to Db::set_pagesize will be ignored and the page size of the existing databases will be used.

The Db::set_pagesize 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

pagesize
  The pagesize parameter sets the database page size.

### Errors

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

EINVAL
  If the method was called after Db::open was called; or if an invalid flag value or parameter was specified.

### Description: Db::get_pagesize

The Db::get_pagesize method returns the page size.

The Db::get_pagesize method may be called at any time during the life of the application.

The Db::get_pagesize 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

pagesizep
  The Db::get_pagesize method returns the page size in pagesizep.

### Class

Db

### See Also

Databases and Related Methods`

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