(statement cache size = 0) == clear statement cache ?

Question

Hi
I ran this test with WLS 8.1. I set to the cache size to 5, and I call a servlet
which invokes a stored procedure to get the statement cached. I then recompile
the proc, set the statement cache size to 0 and re-execute the servlet.
The result is:
java.sql.SQLException: ORA-04068: existing state of packages has been discarded
ORA-04061: existing state of package "CCDB_APPS.MSSG_PROCS" has been invalidated
ORA-04065: not executed, altered or dropped package "CCDB_APPS.MSSG_PROCS"
ORA-06508: PL/SQL: could not find program unit being called
ORA-06512: at line 1
which seems to suggest even though the cache size has set to 0, previously cached
statements are not cleared.
Rgs
Erik

Answer 1

Galen Boyer wrote:
On Fri, 05 Dec 2003, [email protected] wrote:
Galen Boyer wrote:
On 14 Nov 2003, [email protected] wrote:
Hi
I ran this test with WLS 8.1. I set to the cache size to 5,
and I call a servlet which invokes a stored procedure to get
the statement cached. I then recompile the proc, set the
statement cache size to 0 and re-execute the servlet.
The result is:
java.sql.SQLException: ORA-04068: existing state of packages
has been discarded ORA-04061: existing state of package
"CCDB_APPS.MSSG_PROCS" has been invalidated
ORA-04065: not executed, altered or dropped package
"CCDB_APPS.MSSG_PROCS" ORA-06508: PL/SQL: could not find
program unit being called ORA-06512: at line 1
which seems to suggest even though the cache size has set to
0, previously cached statements are not cleared.This is actually an Oracle message. Do the following test.
Open two sqlplus sessions. In one, execute the package.
Then, in the other, drop and recreate that package. Then, go
to the previous window and execute that same package. You
will get that error. Now, in that same sqlplus session,
execute that same line one more time and it goes through. In
short, in your above test, execute your servlet twice and I
bet on the second execution you have no issue.Hi. We did some testing offline, and verified that even a
standalone java program: 1 - making and executing a prepared
statement (calling the procedure), 2 - waiting while the
procedure gets recompiled, 3 - re-executing the prepared
statement gets the exception, BUT ALSO, 4 - closing the
statement after the failure, and making a new identical
statement, and executing it will also get the exception! JoeI just had the chance to test this within weblogic and not just
sqlplus.Note, I wasn't using SQL-PLUS, I wrote a standalone program
using Oracle's driver...
MY SCENARIO:
I had one connection only in my pool. I executed a package.
Then, went into the database and recompiled that package. Next
execution from app found this error. I then subsequently
executed the same package from the app and it was successful.And this was with the cache turned off, correct?
What the application needs to do is catch that error and within
the same connection, resubmit the execution request. All
connections within the pool will get invalidated for that
package's execution.Have you tried this? Did you try to re-use the statement you had,
or did you make a new one?
Maybe Weblogic could understand this and behave this way for
Oracle connections?It's not likely that we will be intercepting all exceptions
coming from a DBMS driver to find out whether it's a particular
failure, and then know that we can/must clear the statement cache.
Note also that even if we did, as I described, the test program I
ran did try to make a new statement to replace the one that
failed, and the new statement also failed.
In your case, you don't even have a cache. Would you verify
in your code, what sort of inline retry works for you?
Joe