Db::set_pagesize |
#include <db_cxx.h>int Db::set_pagesize(u_int32_t pagesize);
Set the size of the pages used to hold items in the database, in bytes. The minimum page size is 512 bytes, and the maximum page size is 64K bytes. 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 interface may not be called after the Db::open interface 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 file, the page size specified must be consistent with the existing databases in the file or an error will be returned.
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.
The Db::set_pagesize method may fail and throw an exception or return a non-zero error for the following conditions:
Called after Db::open was called.
The Db::set_pagesize 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 Db::set_pagesize 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.