[
https://issues.apache.org/jira/browse/HIVE-23048?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17067554#comment-17067554
]
Peter Vary commented on HIVE-23048:
-----------------------------------
For shared locking we can use (shared/exclusive):
* MySQL, PostgreSQL:
{code}
SELECT "MT_COMMENT" FROM "AUX_TABLE" WHERE "MT_KEY1"='commitLock' FOR SHARE;
SELECT "MT_COMMENT" FROM "AUX_TABLE" WHERE "MT_KEY1"='commitLock' FOR UPDATE;
{code}
* SQL Server:
{code}
-- I think we need an index on MT_KEY1
SELECT "MT_COMMENT" FROM "AUX_TABLE" WITH (SERIALIZABLE) WHERE
"MT_KEY1"='commitLock';
SELECT "MT_COMMENT" FROM "AUX_TABLE" WITH (XLOCK) WHERE "MT_KEY1"='commitLock';
{code}
* Oracle, Derby:
{code}
-- We need to create a specific table for this
LOCK TABLE txn_lock IN SHARE MODE;
LOCK TABLE txn_lock IN EXCLUSIVE MODE;
EXCLUSIVE
{code}
> Use sequences for TXN_ID generation
> -----------------------------------
>
> Key: HIVE-23048
> URL: https://issues.apache.org/jira/browse/HIVE-23048
> Project: Hive
> Issue Type: Bug
> Reporter: Peter Vary
> Priority: Major
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
