The DbMpoolFile::sync method writes all pages associated with the
DbMpoolFile, that were marked as modified using DbMpoolFile::put
or DbMpoolFile::set, back to the source file. If any of the modified
pages are also pinned (i.e., currently referenced by this or
another process) DbMpoolFile::sync will ignore them.
The DbMpoolFile::sync method either returns a non-zero error value or throws an exception that
encapsulates a non-zero error value on failure, 0 on success, and returns DB_INCOMPLETE if there were pages which were
modified but which DbMpoolFile::sync was unable to write immediately.
Errors
The DbMpoolFile::sync 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 DbMpoolFile::sync method may fail and either
return DB_RUNRECOVERY or throw an exception encapsulating
DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail
in the same way.