Hello,

Any plans for the fix/workaround? 

I can only think of some pretty messy workarounds like moving my CLOB 
fields to 
a) just VARCHAR(*255*) /though the docs say *The maximum precision is 
Integer.MAX_VALUE<http://www.h2database.com/html/datatypes.html#varchar_type>
*/ 
b) or to BLOB (may behave the same way as CLOB) 
c) or to BINARY (looks promising).



On Tuesday, December 4, 2012 6:59:08 PM UTC+2, Nick99 wrote:
>
> It seems the problem is with MVCC.
>
> The test is not failing for 30s on my system with: "jdbc:h2:db/test01;MVCC=
> *FALSE*;MULTI_THREADED=0;LOCK_MODE=3;LOCK_TIMEOUT=20000;"
>
> All isolation levels fail for (in the 1-5s 
> timeframe): "jdbc:h2:db/test01;MVCC=*TRUE;*
> MULTI_THREADED=0;LOCK_MODE=3;LOCK_TIMEOUT=20000;" 
> Connection.TRANSACTION_READ_UNCOMMITTED
> Connection.TRANSACTION_READ_COMMITTED
> Connection.TRANSACTION_REPEATABLE_READ
> Connection.TRANSACTION_SERIALIZABLE
>
> On Tuesday, December 4, 2012 11:01:37 AM U
> TC+2, Noel Grandin wrote:
>>
>> Hmmm, I think what is happening here is that when in MVCC mode with 
>> transaction isolation level TRANSACTION_READ_COMMITTED, the session is 
>> somehow seeing LOB entries that have already been deleted. 
>>
>> Thomas, does that ring any bells? 
>>
>> I've been through the code paths that end up in LobStorage, but I can't 
>> see any obvious problems. 
>>
>> On 2012-12-03 09:58, Noel Grandin wrote: 
>> > Nice work on creating the test case! 
>> > 
>> > Interesting, this is a genuine bug somewhere in the LOB code, and it 
>> > manifests even with MVCC=false. 
>> > 
>> > The only short-term fix I can see is to set your transaction isolation 
>> > to  TRANSACTION_REPEATABLE_READ. 
>> > 
>> > Thomas, I further reduced the test-case, and I'm including it here. 
>> > Note that (for me) it did not fail every single time. I normally let 
>> > it run for about 15 seconds, and then terminate and try again. 
>> > I get a failure rate of about 50%. 
>> > 
>>
>>

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