I'm new to MySQL mailing lists. Is there a more appropriate list for
this type of question?
thanks
-nikita
Nikita Tovstoles wrote:
Hi,
I'm running into lost of DB deadlocks would really appreciate answers
to the questions below which will help me diagnose the problem. I am
running MySQL 5 InnoDB, SERIALIZABLE mode.
Let's say we have:
1.TX1 START //assume autocommit is off
2.TX1 read on TableA
3.TX1 update on TableA
4.TX1 read on TableB
5.TX1 COMMIT
Is the following correct?
-In step2, TX1 obtains a SHARED lock. Is it applied to all rows in
TableA or only those returned by select statement?
-In step3, TX1 obtains an EXCLUSIVE lock. Does that lock out all of
TableA or only those rows that are being updated?
-In step4, does TX1 apply SHARED or EXCLUSIVE lock? is the lock
applied to all of TableB or only to rows returned by the select
statement?
In general what is the effect (w/r/t locking) on selects performed
after a write operation within the same TX?
thanks a lot!
-nikita
Nikita Tovstoles http://doppelganger.com [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]
Doppelganger, Inc.
Re: effects of aquiring exclusive lock on subsequent reads inside same TX?
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