Anyone dealt with address not mapped to object errors?

Hi all,

Of the many databases I support under Oracle 7.2.3-8.1.6.2 only one database is currently giving me grief that I can't get a handle on. I should mention that I can reproduce the problem at will on our production server and not anywhere else under any Oracle version.

I have Oracle support working on the issue, but it's been a week and they have nothing to tell me yet.

The database version is 8.1.6.2 recently upgraded from 7.3.4.3 with the migration utility. It runs on a sun 6500, 10 processors (336mhz, 10 gb ram solaris 2.6 with all required patches)

The problem is that the database is core dumping about 20-30 times per day (doesn't crash). The trace files reveal 7445 errors (address not mapped to object) followed by a 600 error. There seem to be about 6 or so distinct sql statements in memory during the error(one statement per trace file/core dump). Any one of these statements can cause the error.

I have run these statements from sqlplus and cannot reproduce the problem. Today, however, one of my own statements blew up with a 3113 error(end of file on communication channel). Sure enough, there was a core dump and trace file with the same errors as all the others. The only peculiar thing about the statement I was running is that it was a piece of dynamic sql that had a syntax error in it. Under any other DB the error is "from clause not found where expected"(or something similar). On this one DB though and end of file on communication channel error occurs. I can reproduce this error at will by running this statement.

I set up a test database where I migrated from 7.3.4 to 8.1.6.2 using the same data our production system had. The init.ora parameters are identical except lesser block buffers and one less rollback segment. I cannot reproduce the error there.

Other tidbits are that the application causing these errors connects to the DB via SQLNet and my SQLPlus session was a direct connect so SQLNet/network issues don't appear to be an issue.

I suspect the 3113 error is being caused by the 7445 and 600 errors disconnecting the process from the database.

All the sql encountering this problem are select statements, no dml.(so far)

So, why am I telling you all this? I am hoping that per chance one of you have encountered something similar that might help me get a handle on the situation.

TIA,

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Dave A