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From:Yves Goergen Date:November 13 2007 5:17pm
Subject:Re: Transactions and locking
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On 13.11.2007 17:39 CE(S)T, Baron Schwartz wrote:
> Yves Goergen wrote:
>> Row level locking can only lock rows that exist. Creating new rows (that
>> would have an influence on my MAX value) are still possible and thus row
>> level locking is not what I need. I really need locking an entire table
>> for every other read or write access.
> 
> InnoDB can also lock the gap, which will prevent new rows that would 
> have been returned by the SELECT.  The manual has more info on this in 
> the section on consistent reads in InnoDB.  FOR UPDATE will do what you 
> need.

I've read about that "gap" but it sounded like "the place [somewhere]
before a record where one could insert a new record into". Not sure what
that should be. I'm not aware of the InnoDB internals. I know that
usually (?) when a new record is stored, it is written to where is
enough space for it, linked from a free pointer index. If one is locked,
another one might be used. Order doesn't matter in relational databases.

-- 
Yves Goergen "LonelyPixel" <nospam.list@stripped>
Visit my web laboratory at http://beta.unclassified.de

Thread
Transactions and lockingYves Goergen12 Nov
  • Re: Transactions and lockingMartijn Tonies12 Nov
  • Re: Transactions and lockingPerrin Harkins12 Nov
    • Re: Transactions and lockingYves Goergen12 Nov
      • Re: Transactions and lockingPerrin Harkins12 Nov
      • Re: Transactions and lockingYves Goergen12 Nov
        • Re: Transactions and lockingYves Goergen12 Nov
          • Re: Transactions and lockingPerrin Harkins12 Nov
            • Re: Transactions and lockingYves Goergen12 Nov
              • Re: Transactions and lockingPerrin Harkins13 Nov
                • Re: Transactions and lockingYves Goergen13 Nov
                  • mysqlhotcopyMalka Cymbalista13 Nov
                  • Re: Transactions and lockingBaron Schwartz13 Nov
                    • Re: Transactions and lockingmark addison13 Nov
                      • Re: Transactions and lockingYves Goergen13 Nov
                        • Re: Transactions and lockingBaron Schwartz13 Nov
                          • Re: Transactions and lockingYves Goergen13 Nov
                            • Re: Transactions and lockingBaron Schwartz13 Nov
                          • Re: Transactions and lockingPerrin Harkins13 Nov
                            • Re: Transactions and lockingYves Goergen13 Nov
                              • Re: Transactions and lockingBaron Schwartz13 Nov
                                • Re: Transactions and lockingYves Goergen13 Nov
                    • Re: Transactions and lockingYves Goergen13 Nov
                    • Re: Transactions and lockingYves Goergen13 Nov
                      • Re: Transactions and lockingBaron Schwartz13 Nov
                        • Re: Transactions and lockingYves Goergen13 Nov
                        • Re: Transactions and lockingYves Goergen13 Nov
                          • Re: Transactions and lockingPerrin Harkins13 Nov
  • Re: Transactions and lockingMartijn Tonies13 Nov
  • Re: Transactions and lockingMartijn Tonies14 Nov
    • Re: Transactions and lockingYves Goergen15 Nov
  • Re: Transactions and lockingMartijn Tonies15 Nov
Re: Transactions and lockingYves Goergen13 Nov
  • Re: Transactions and lockingPerrin Harkins13 Nov