Queries fail and database goes into recovery, the reason for the failure as per the database logs is indicated due to the below error message:
dx1413805,x106257143,sx1,"PANIC","XX000","proclock table corrupted (lock.c:1251)",,,,,,,0,,"lock.c",1251,"Stack trace: 1 0xa65efa postgres + 0xa65efa 2 0xa67fa8 postgres elog_finish + 0xb8 3 0x8dea95 postgres RemoveFromWaitQueue + 0x125 4 0x8e2b61 postgres ProcReleaseLocks + 0xd1 5 0xaac238 postgres ResourceOwnerRelease + 0x308 6 0x4f63cd postgres AbortTransaction + 0x41d 7 0x4f9935 postgres AbortCurrentTransaction + 0x25 8 0x9056aa postgres PostgresMain + 0x78a 9 0x86dd61 postgres + 0x86dd61 10 0x874410 postgres PostmasterMain + 0x1870 11 0x779eea postgres main + 0x4da 12 0x365a01ecdd libc.so.6 __libc_start_main + 0xfd 13 0x47ab59 postgres + 0x47ab59
This a known bug with the version below 4.2.5.x would request to upgrade to avoid the issue.
This issue is fixed in Greenplum Database 4.2.5.x. , upgrade to a version later than 4.2.5.x.
Workaround
Restart the database