...In a nutshell:
CREATE TEMPORARY TABLE foo AS SELECT DISTINCT ON (x, y, z) * FROM bar;
crashes the backend and screws up data pages associated with the catalog under
7.4.1.
Works for me ...
Perhaps providing a specific test case would help.Could you give me a bit of direction?
I dumped the data associated with the tables involved from database "Development", loaded them into a new database "Test" and ran the script which causes the backend to crash and it worked fine, no errors. This was on the same machine.
I then run the same script against the database "Development" (from which I had just dumped the data and relevant schema for "Test") and I get a crashed backend. Here's a backtrace:
Program received signal SIGSEGV, Segmentation fault. 0x0806fb52 in nocachegetattr ()
#0 0x0806fb52 in nocachegetattr () #1 0x0810186e in execTuplesMatch () #2 0x081115dc in ExecUnique () #3 0x08104cf8 in ExecProcNode () #4 0x0810356d in ExecutePlan () #5 0x08102968 in ExecutorRun () #6 0x08178682 in ProcessQuery () #7 0x08179144 in PortalRunMulti () #8 0x08178afb in PortalRun () #9 0x08175545 in exec_simple_query () #10 0x08177c09 in PostgresMain () #11 0x08151b9b in BackendFork () #12 0x081515a3 in BackendStartup () #13 0x0814faa8 in ServerLoop () #14 0x0814f171 in PostmasterMain () #15 0x0811f5b5 in main () #16 0x42015967 in __libc_start_main () from /lib/i686/libc.so.6 (gdb)
I don't get it. I had received this error in the "Development" database while running the application. I thought perhaps it was bad blocks or flaky RAM. So I *wiped out* the database cluster after running fsck and restored from the "Production" database dump copied from another machine. I ran the application again and it crashed at the exact same place.
I can send you the query and the schema, but as I've said, when I load the schema & data associated with the tables and views involved with this query from "Development" into a new "Test" database in the same cluster, it executes fine???
I'll try and dump the entire database and restore it on a third machine and see if the query crashes that backend as well. But it will take a bit of time. If it does crash what does that mean? If not, what does that mean?
Mike Mascari
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