# DB->sync

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    #include <db.h>

    int
    DB->sync(DB *db, u_int32_t flags);

# Description

The DB->sync function flushes any cached information to disk.

If the database is in memory only, the DB->sync function 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 function returns a non-zero error value on failure, 0 on success, and DB_INCOMPLETE if the underlying database still has dirty pages in the cache. (The only reason for a return of DB_INCOMPLETE is if another thread of control was writing pages in the underlying database file at the same time as the DB->sync function was being called. For this reason, a return of DB_INCOMPLETE can normally be ignored, or, in cases where it is a possible return value, there may be no reason to call DB->sync.)

# Errors

The DB->sync function may fail and return a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

The DB->sync function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions. If a catastrophic error has occurred, the DB->sync function may fail and return DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.

# See Also

db_create, DB->close, DB->cursor, DB->del, DB->err, DB->fd, DB->get, DB->get_byteswapped, DB->get_type, DB->join, DB->key_range, DB->open, DB->put, DB->remove, DB->set_bt_compare, DB->set_bt_minkey, DB->set_bt_prefix, DB->set_cachesize, DB->set_dup_compare, DB->set_errcall, DB->set_errfile, DB->set_errpfx, DB->set_flags, DB->set_h_ffactor, DB->set_h_hash, DB->set_h_nelem, DB->set_lorder, DB->set_malloc, DB->set_pagesize, DB->set_paniccall, DB->set_realloc, DB->set_re_delim, DB->set_re_len, DB->set_re_pad, DB->set_re_source, DB->stat, DB->sync, DB->upgrade and DB->verify.`

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