On CVS tip: $ postgres --single -Ddata postgres
PostgreSQL stand-alone backend 8.2devel Segmentation fault (core dumped) $ gdb -c core.18119 (gdb) bt #0 pgstat_report_activity (cmd_str=0x67d25e "<IDLE>") at pgstat.c:1484 1484 beentry->st_changecount++; (gdb) bt #0 pgstat_report_activity (cmd_str=0x67d25e "<IDLE>") at pgstat.c:1484 #1 0x000000000056db8c in PostgresMain (argc=1, argv=0x8657d8, username=0x867030 "qqzhou") at postgres.c:3132 #2 0x000000000050c918 in main (argc=4, argv=0x8657d0) at main.c:372 (gdb) p beentry $1 = (volatile PgBackendStatus *) 0x0 Ooops, guess we forget to handle the single user mode in "current-status information in shared memory" patch ... Regards, Qingqing ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend