Re: jdbc icc connection cache

From: <kuassi.mensah_at_gmail.com>
Date: Sun, 25 May 2008 11:05:34 -0700 (PDT)
Message-ID: <f387b829-9e1d-4102-ac7f-99319acdd5f2@q24g2000prf.googlegroups.com>


On May 23, 4:39 pm, "news.verizon.net" <kenned..._at_verizon.net> wrote:
> <kuassi.men..._at_gmail.com> wrote in message
>
> news:d138c3d8-4c4d-48bc-a618-284376deb856_at_s33g2000pri.googlegroups.com...
>
> > On May 22, 8:34 pm, "news.verizon.net" <kenned..._at_verizon.net> wrote:
> >> <kuassi.men..._at_gmail.com> wrote in message
>
> >>news:eb45f9a5-352a-447c-b48e-91a394027397_at_u6g2000prc.googlegroups.com...
>
> >> > On May 21, 2:20 pm, "jim. dot scuba dot kennedy at gee male dot com"
> >> > <jim.scuba.kenn..._at_gmail.com> wrote:
> >> >> Does anyone have any experience using Oracle's JDBC ICC (implicit
> >> >> connections cache) with RAC? We are on 10G. What I am looking for is
> >> >> if anyone is using this and their overall experience. Good bad, etc.
> >> >> Thanks,
> >> >> Jim Kennedy
>
> >> > Hi,
>
> >> > I am the Oracle JDBC product manager, not a customer.
> >> > I don't have permission to give names but there are happy customers
> >> > using ICC with RAC as well as Fast Connection Failover and Runtime
> >> > Connection Load Balancing.
> >> > Fwiw, my blog entry
> >> >http://db360.blogspot.com/2007/01/is-your-java-application-failoverpr...,
> >> > gives a summary of how it works and how to enable it.
>
> >> > Kuassi
> >> > - bloghttp://db360.blogspot.com
> >> > - bookhttp://www.amazon.com/exec/obidos/ASIN/1555583296
> >> > -http://www.savedarfur.org/content
>
> >> Thanks. If you know of any customers that would be willing to provide
> >> feedback to me directly - I would not diseminate the information
> >> elsewhere -
> >> please have them contact me. jimk at snapnames dot com. We have been
> >> struggling with a non-rac related isse with the thin jdbc driver for a
> >> couple of years on a known issue. (create a type in schema A, grant
> >> execute
> >> on type to schema B. Create a synonym in schema B for the type defined
> >> in
> >> schema A. The JDBC thin driver does not handle this case. It turns out
> >> the
> >> 11g jdbc driver finally does, but Oracle recommends not using it because
> >> of
> >> a sever memory leak. Subsequently, we have had to write a lot of code to
> >> get around this issue and the QA manager is gun shy with some Oracle
> >> products. Which has lead me to my assignment to get some feedback from
> >> other customers. (not to be made public, to be kept in confidence) The
> >> QA
> >> manager wants to know if anyone actually uses this in production and
> >> wants
> >> to get feed back from them.
>
> >> I know I have rambled a bit. I have booked marked your site and am
> >> keeping
> >> a copy of your reply for reference.
> >> Thanks,
> >> Jim Kennedy
>
> > Jim,
>
> > Will do.
>
> > There is no known memory leak with 11g JDBC-Thin; The recommendation
> > is to use full/complete schema name instead of synonym becoz it takes
> > a couple of round trips to get the complete information from the
> > server.
>
> > Kuassi
>
> I don't have the metalink doc id with me, but when our other dba was
> researching using the 11G jdbc thin driver he came across the doc. on it.
> (we are using 10G as the server not 11G as the server) (short on details,
> it was related to an SR with a creation date of around the end of April).
> When he asked the Oracle support person about it they recommended to NOT use
> the 11g jdbc thin driver because of a known memory leak.(maybe there isn't
> maybe there is)
>
> You have to add the schema in front of the type because it doesn't work if
> you don't. It is a bug that has been there at lease pre 11G JDBC driver. (I
> think we did confirm that it was fixed in 11G) Yes, it may be faster during
> the describe to have the schema prefixed to the object type, but it should
> not be required. It is not required if I do it from a tool like sqlplus for
> example. (assuming proper rights and synonym creation etc.) I know this is
> going to sound silly, but it would be a major code rewrite to change all the
> Java objects to use an schema prefix (for a schema other than the one they
> are connecting to.) Management does not want to spend the large cost to
> rewrite and retest to accomadate the schema prefix when the question is "Why
> doesn't Oracle fix something that should work?" (This is a known issue.)
>
> Not trying to bitch ; just giving you customer feed back because I think it
> would be helpful to Oracle. I do like the product and have had excellent
> experiences with it. I have used the db since version 6 and have had some
> very positive customer support experiences.
> Thanks,
> Jim Kennedy

We need more details:
- There were a number of bugs in the area of synonyms for object types and collections that have been fixed; which releases of JDBC and RDBMS
- TAR number or a test case that reproduces the problem; you may email me (kuassi.mensah_at_oracle.com) Received on Sun May 25 2008 - 13:05:34 CDT

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