DB_HISTORY_SIZE
#if DB_HISTORY_SIZE != 0
#if DB_HISTORY_SIZE != 0
#if DB_HISTORY_SIZE != 0
#if DB_HISTORY_SIZE != 0
char db_history[DB_HISTORY_SIZE]; /* start of history buffer */
int db_history_size = DB_HISTORY_SIZE;/* size of history buffer */
#ifndef DB_HISTORY_SIZE