DB_MAGIC
if (DB_HDR(hdp)->magic != DB_MAGIC || DB_HDR(hdp)->vers != DB_VERSION) {
DB_HDR(hdp)->magic = DB_MAGIC;
#define DB_VERSION_0_9 (DB_MAGIC|(DB_MAJOR<<8)|9)
#define DB_CURRENT_VERSION (DB_MAGIC|DB_MAJOR<<8|DB_MINOR)