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From:Mats Kindahl Date:January 19 2010 7:38pm
Subject:Re: Don't replicating without USE db;
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Song Voong wrote:
> Does this only happen on 5.0? In 5.1 using the row replication will fix
> this?

This change is only for row-based, for statement-based the behavior is
the same in 5.1 as in 5.0 (and earlier versions).

Just my few cents,
Mats Kindahl

> 
> On Tue, Jan 19, 2010 at 2:33 AM, Mats Kindahl <mats@stripped> wrote:
> 
>>
>> Alper Oguz wrote:
>>> Thank you for explanations Rick.
>>>
>>> But I don't understand such as Case 2. "INSET INTO anotherdb.tbl..."
>>> contains database information. Why it's not write that info to the
>>> binlogs? Why Mysql still need to USE db command? I think it's very
>>> stupidly.. :(
>> I'm not going to say that it's not stupid (because it is), but to
>> extracting the database require additional processing even for
>> statements that do not require it. This introduces a penalty to all
>> statement even if they do not qualify the table name.
>>
>> In addition, multi-table updates will have problem in deciding if the
>> statement would be filtered or not if the tables are in different
>> databases, and using a special rule for updates would just be confusing.
>>
>> These two things, taken together, was probably the reason that it was
>> not added initially.
>>
>> Now, there are users that rely on this behavior and therefore it
>> cannot be removed.
>>
>> If you want to have filtering correct, use row-based replication.
>> There the filtering is on the actual table and database, and not on
>> the current database.
>>
>> Just my few cents,
>> Mats Kindahl
>>
>>> thank you again
>>>
>>> Alper
>>>
>>>
>>> Suresh Kuna wrote On 07-01-2010 07:40:
>>>> Good use case explanation Rick.
>>>>
>>>> Suresh Kuna
>>>> MySQL DBA
>>>>
>>>> On Thu, Jan 7, 2010 at 12:13 AM, Rick James <rjames@stripped
>>>> <mailto:rjames@stripped>> wrote:
>>>>
>>>>     Assuming you have binlog/replication-do/ignore...
>>>>     (If you don't, then everything gets replicated.)
>>>>
>>>>     Case 1:
>>>>     USE dbname;
>>>>     INSERT INTO dbname.tbl ...
>>>>     This case is rather redundant.  Except that replication looks at the
>>>>     USE to decide whether to replicate the INSERT.  (One can argue that
>>>>     this is a stupid design.  It does bite a lot of users.)
>>>>
>>>>     Case 2:
>>>>     USE dbname;
>>>>     INSERT INTO anotherdb.tbl ...
>>>>     The INSERT works with 'anotherdb', but replication could be fooled
>>>>     (see above).
>>>>
>>>>     Case 3:
>>>>     USE dbname;
>>>>     INSERT INTO tbl ...
>>>>     Here, 'dbname' is needed to say which 'tbl' is to be INSERTed into.
>>>>       There is no ambiguity in replication.
>>>>
>>>>     Case 4:
>>>>     INSERT INTO onedb.tbl SELECT * FROM anotherdb.foo;
>>>>     If onedb is replicated but anotherdb is not, you have a problem.
>>>>
>>>>     Cases:
>>>>     LOAD DATA; SELECT INTO OUTFILE; etc
>>>>     These have various issues.
>>>>
>>>>
>>>>     Rick James
>>>>     MySQL Geeks - Consulting & Review
>>>>
>>>>
>>>>
>>>>      > -----Original Message-----
>>>>      > From: Database System [mailto:database100@stripped
>>>>     <mailto:database100@stripped>]
>>>>      > Sent: Wednesday, January 06, 2010 10:25 AM
>>>>      > To: Alper Oguz; replication@stripped
>>>>     <mailto:replication@stripped>; Rick James
>>>>      > Subject: RE: Don't replicating without USE db;
>>>>      >
>>>>      > If we use USE db, then in the code still use db.table, will
>>>>      > that able to be replicated?
>>>>      >
>>>>      > --- On Wed, 1/6/10, Rick James <rjames@stripped
>>>>     <mailto:rjames@stripped>> wrote:
>>>>      >
>>>>      > > From: Rick James <rjames@stripped
>>>>     <mailto:rjames@stripped>>
>>>>      > > Subject: RE: Don't replicating without USE db;
>>>>      > > To: "Alper Oguz" <alper2@stripped
> <mailto:alper2@stripped>>,
>>>>     replication@stripped
> <mailto:replication@stripped>
>>>>      > > Date: Wednesday, January 6, 2010, 11:07 AM
>>>>      > > Workaround:  issue "USE db"
>>>>      > > before the INSERT.
>>>>      > >
>>>>      > >
>>>>      > > Rick James
>>>>      > > MySQL Geeks - Consulting & Review
>>>>      > >
>>>>      > >
>>>>      > >
>>>>      > > > -----Original Message-----
>>>>      > > > From: Alper Oguz [mailto:alper2@stripped
>>>>     <mailto:alper2@stripped>]
>>>>      > > > Sent: Wednesday, January 06, 2010 6:15 AM
>>>>      > > > To: replication@stripped
>>>>     <mailto:replication@stripped>
>>>>      > > > Subject: Don't replicating without USE db;
>>>>      > > >
>>>>      > > > Hello,
>>>>      > > >
>>>>      > > > I've two Mysql 5 servers that work on master-master
>>>>      > > > replication. Both are
>>>>      > > > Mysql 5.0.51a on Debian 5 machines.
>>>>      > > >
>>>>      > > > I've discover this issue on my system:
>>>>      > > >
>>>>      > > > http://bugs.mysql.com/bug.php?id=37483
>>>>      > > >
>>>>      > > > Our developers sometimes use queries like INSERT
> INTO
>>>>      > >
>>>>      > > > db.table... and these
>>>>      > > > rows aren't replicated to the second server.
>>>>      > > >
>>>>      > > > There is a suggestion to remove binlog-do-db lines
>>>>      > > from
>>>>      > > > my.cnf end of that bug
>>>>      > > > entry. (I know, this is not a bug)
>>>>      > > >
>>>>      > > > But how to work replication without binary logs?
> Could
>>>>      > > you
>>>>      > > > please inform me?
>>>>      > > >
>>>>      > > > thank you
>>>>      > > >
>>>>      > > >
>>>>      > > > --
>>>>      > > > Alper Oguz
>>>>      > > > alper2@stripped <mailto:alper2@stripped>
>> --
>> Mats Kindahl
>> Senior Software Engineer
>> Database Technology Group
>> Sun Microsystems
>>
>> --
>> MySQL Replication Mailing List
>> For list archives: http://lists.mysql.com/replication
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>>
>>
> 

-- 
Mats Kindahl
Senior Software Engineer
Database Technology Group
Sun Microsystems
Thread
Don't replicating without USE db;Alper Oguz6 Jan
  • RE: Don't replicating without USE db;Rick James6 Jan
    • RE: Don't replicating without USE db;Database System6 Jan
      • RE: Don't replicating without USE db;Rick James6 Jan
        • Re: Don't replicating without USE db;Suresh Kuna7 Jan
          • Re: Don't replicating without USE db;Alper Oguz19 Jan
            • Re: Don't replicating without USE db;Mats Kindahl19 Jan
              • Re: Don't replicating without USE db;Song Voong19 Jan
                • Re: Don't replicating without USE db;Rick James19 Jan
                  • Re: Don't replicating without USE db;Jeff Smelser19 Jan
                • Re: Don't replicating without USE db;Mats Kindahl19 Jan