Re: SQL query brings database server down

On Tue, 13 Oct 1998, Robert Douglas wrote: > Just out of curiosity, I ran the query on our development machine (Solaris 2.5 > ODS 7.12.) Sure enough it thrashed Informix, but with these entries in the log: > > 14:27:44 Who:Session(11425, rdouglas@hercules, 5218, 9113316) > Thread(12032, sqlexec, 891280, 1) > 14:27:44 Results: OnLine must abort > 14:27:44 Action: Reinitialize shared memory > 14:27:44 See Also: /work/dbtemp/af.2f00c5cf, shmem.2f00c5cf.0 > 14:27:54 rsinit.c, line 9182, thread 12032, proc id 11401, Segmentation > Violation. > 14:27:54 PANIC: Attempting to bring system down So, just out of curiosity, I ran an adapted version of the query on my desktop Sparc 20 running Solaris 2.6 and OnLine 7.24.UC1 against the stores7 database, with the query: SELECT fname, lname, address1 FROM customer WHERE "John" IN (fname); and was not able to detect any problems... It suggests that the bug was fixed between the 7.1x and 7.2x families. I've no idea which version fixed it. And the fix was not to generate a syntax error but to accept the query and generate no output... This might need to be reported as a bug, still, but at least the engine doesn't crash. > > Bart Van der Cruyssen <Bart.VanderCruyssen@rug.ac.be> writes > > >We are working with INFORMIX Online Version 7.10. > > >We found out that a query like : > > > > > >SELECT first_name, last_name, address > > >FROM customers > > >WHERE "John" IN (first_name);> > > > > >which is clearly syntacticly incorrect (but students try out such things), > > >does NOT result in a 'syntax error'. > > >Instead, the server goes down, reporting in "online.log" (the user name is > > >changed): > > > > > >10:20:50 Assert Failed: Internal Error - Segmentation Violation > > >10:20:50 Who: Session(20, name@server, 15722, 5) > > > Thread(44, sqlexec, a0ff514, 1) > > >10:20:50 Results: OnLine must abort > > >10:20:50 Action: Reinitialize shared memory > > >10:20:50 See Also: /tmp/af.9cba41, shmem.9cba41.0 > > >10:20:51 rsdebug.c, line 3591, thread 44, proc id 23155, Segmentation > > >Violation. > > >10:20:51 PANIC: Attempting to bring system down> > > > > >In my opinion, no possible input for a query (correct or incorrect) should > > >be able to bring down the database server, especially when executed from > > >within dbaccess (one of informix' own database tools). No possible input for a query should bring the server down. Period. It can refuse to answer, or generate an error; it should not bring the server down... > > >These are (some of) my questions: > > >- Have others experienced the same problem ? Yes, but others have systems which are not afflicted. > > >- Is this a known bug ? (Note that the log file always refers to : > > >'rsdebug.c', line 3591.) Dunno. > > >- Is this problem solved in later versions of the product ? > > Probably, 7.10 is an early 7.x release and there have been a lot of > > fixes done since then, move to 7.30.UC3.. Yes. > > >- Are there any workarounds, except not trying such queries ? > > No. Probably not. > > >- Are there other "look-like" SQL-queries known to bring down the system ? I don't know of any, but I've neither tried very hard nor specifically gone looking for records from others. Yours, Jonathan Leffler (jleffler@informix.com) #include <witticism.h> Guardian of DBD::Informix v0.60 -- http://www.perl.com/CPAN Informix IDN for D4GL & Linux -- http://www.informix.com/idn