Explicit Locking Question

Dear all
I have a question about <<Developer’s Guide>> Explicit Locking (27-3)：
"In a replicated cache, puts are blocked, but they are not blocked in a partitioned cache. "
I want to know why "puts are not blocked in a partitioned cache."
Thanks

wangjw wrote:
Dear all
I have a question about <<Developer’s Guide>> Explicit Locking (27-3)：
"In a replicated cache, puts are blocked, but they are not blocked in a partitioned cache. "
I want to know why "puts are not blocked in a partitioned cache."
ThanksThe normal behaviour is that lock does not block anything other than another lock.
The put-blocking behaviour at replicated caches is an anomaly which may be necessary due to backward compatibility reasons, or possibly a necessity due to the message flow for mutating operations in a replicated cache.
So the question really would be why puts are blocked in a replicated cache, and I would also be interested in the answer, although I have my guesses.
Best regards,
Robert

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Edited by: rkuppa on May 26, 2013 7:10 AM
Edited by: rkuppa on May 26, 2013 7:11 AM
Edited by: rkuppa on May 26, 2013 4:23 PM

>
I'm trying to understand locking on "other end of FK", i..e. operations on child table in 11g. Database version 11.2.0.2.0
>
Here are two articles about that by Jonathan Lewis
http://jonathanlewis.wordpress.com/2010/06/21/locks/
http://jonathanlewis.wordpress.com/2010/02/15/lock-horror/
>
Table bal_fct has columns(branch id, acct id, cust id, bal dt, bal ccy id, stmt id, bal amt). PK/Unique index on branch id, acct id, cust id, bal dt, bal ccy id, stmt id in that order. All these columns have FKs. No index on these FKs. There is a bitmap index on acct_id.
An ETL job is doing inserts in bal fct table (child). As I understand, any operation on child table would take RX(mode 3) on parent tables in 11g.
I queried locks taken. It is taking mode 3 lock on all the tables EXCEPT ACCT(acct_id). Why? I assumed that it will take also mode 3 lock on ACCT also. I have read in other threads that bitmap index really don't count in these discussions.
>
You won't get row level locks when a bitmap index is used.
Can you edit your post and clarify it a bit.
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