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https://issues.apache.org/jira/browse/OPENJPA-182?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12487098
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Michael Dick commented on OPENJPA-182:
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I have no practical experience with Sybase, but I did find this in their
TransactSQL user's guide :
"Changing the isolation level for a query
You can change the isolation level for a query by using the at isolation clause
with the select or readtext statements. The at isolation clause supports
isolation levels 0, 1, and 3. It does not support isolation level 2. The read
uncommitted, read committed, and serializable options of at isolation represent
isolation levels as listed below:
at isolation option Isolation level
read uncommited 0
read committed 1
serializable 3
For example, the following two statements query the same table at isolation
levels 0 and 3, respectively:
select *
from titles
at isolation read uncommitted
select *
from titles
at isolation serializable"
There's more information online here:
http://manuals.sybase.com/onlinebooks/group-as/asg1250e/sqlug/@Generic__BookTextView/53911;hf=0
> db2 update lock syntax WITH <isolation> USE AND KEEP UPDATE LOCKS
> ------------------------------------------------------------------
>
> Key: OPENJPA-182
> URL: https://issues.apache.org/jira/browse/OPENJPA-182
> Project: OpenJPA
> Issue Type: New Feature
> Components: jdbc
> Environment: db2 database driver for zOS, AS400, Unix, Windows, Linux
> Reporter: David Wisneski
> Assigned To: David Wisneski
> Attachments: OPENJPA-182.patch, openJPA182.patch
>
>
> A while back we changed the syntax of update locking from FOR UPDATE OF to
> WITH RS USE AND KEEP UPDATE LOCKS. Additional changes are required because
> 1. if isolation=serializable is configured, then the syntax should be WITH
> RR USE AND KEEP UDPATE LOCKS
> 2. when using DB2/400 on iSeries machines, the syntax is WITH RS USE AND
> KEEP EXCLUSIVE LOCKS or WITH RR USE AND KEEP EXCLUSIVE LOCKS because DB2/400
> only supports read or exclusive locks.
> 3. DB2 supports both a FETCH FIRST ROWS and update LOCKS clauses.
> So we change supportsLockingWithSelectRange = true in the
> AbstractDB2Dictionary class and change the DB2Dictionary to append the
> correct LOCKS syntax depending on vendor, release and isolation level.
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