#define TDB_BIGENDIAN 32 /* header is big-endian (internal use) */
#define TDB_NOSYNC 64 /* don't use synchronous transactions */
#define TDB_SEQNUM 128 /* maintain a sequence number */
+#define TDB_VOLATILE 256 /* Activate the per-hashchain freelist, default 5 */
#define TDB_ERRCODE(code, ret) ((tdb->ecode = (code)), ret)