Berkeley DB: Db::sync
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btr ee,hash,hashing,transaction,transactions,locking,logging,access method,access me thods,java,C,C++

# Db::sync

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    #include <db_cxx.h>

    int
    Db::sync(u_int32_t flags);

# Description

The Db::sync method flushes any cached information to disk.

If the database is in memory only, the Db::sync method has no effect and will always succeed.

The flags parameter is currently unused, and must be set to 0.

See Db::close for a discussion of Berkeley DB and cached data.

The Db::sync method either returns errno or throws an exception that encapsulates an errno on failure, and 0 on success.

# Errors

If a fatal error occurs in Berkeley DB, the Db::sync method may fail and either return DB_RUNRECOVERY or throw an exception encapsulating DB_RUNRECOVERY, at which point all subsequent database calls will also fail in the same way. Methods marked as returning errno will, by default, throw an exception that encapsulates the error information. The default error behavior can be changed, see DbException.

The Db::sync method may fail and throw an exception for any of the errors specified for the following Berkeley DB and C library functions: Db::cursor, Db::get, Db::sync, DBcursor->c_close(3), __account_page(3), close(3), dbenv->db_paniccall(3), fcntl(3), fflush(3), fprintf(3), free(3), func(3), DbLockTab::get, DbLock::put, DbLockTab::vec, DbLog::put, malloc(3), memcpy(3), memmove(3), DbMpoolFile::get, DbMpoolFile::put, DbMpoolFile::set, DbMpoolFile::sync, memset(3), munmap(3), open(3), realloc(3), sigfillset(3), sigprocmask(3), strerror(3), unlink(3), vfprintf(3), vsnprintf(3), and write(3).

In addition, the Db::sync method may fail and throw an exception or return errno for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

# Class

Db

# See Also

Db::close, Db::cursor, Db::del, Db::fd, Db::get, Db::get_byteswapped, Db::get_type, Db::join, Db::open, Db::put, Db::stat and Db::sync.`