On 3/30/2016 1:26 PM, Lentes, Bernd wrote:
----- On Mar 30, 2016, at 7:04 PM, Reindl Harald h.rei...@thelounge.net wrote:
So i should use the default (autocommit=1)?
no, you should what is appropriate for your application
if you don't care about inserts/updates triggered by let say a
webrequest are half written due a crash or restart use autocommit
Autocommit means that every statement is committed implicitly. Right ?
Commit works only in conjunction with InnoDB tables and transaction. That's
what i understand.
I thought when i make e.g. an insert into a InnoDB table, and that insert is
not done completely (due to a crash, restart, what ever)
it is rolled back automatically after the restart. Is that wrong ?
it depends: If the transaction made it into the Binary Log (if it is
enabled) and the REDO log as "committed", then InnoDB will finish the
commit (put the actual data in its proper place in the data files) after
recovery. If not, it will rollback and your data remains as it was.
http://dev.mysql.com/doc/refman/5.6/en/innodb-recovery.html
if you care that all or nothing is written use transactions
if you care that way don't mix non-transactional tables with innodb
I'm planning to convert the MyISAM tables to InnoDB.
That will solve many of your data consistency problems (particularly
those related to how things are recorded in the Binary Log), presuming
you surround changes that involve multiple commands with transaction
control commands.
If your sets of data changes only need one command to complete, then the
overhead of issuing explicit START TRANSACTION and COMMIT commands is
just going to create work you don't need for your workflow. If you need
more than one command to make a complete and consistent update to your
data, then use a transaction. If not, operating in autocommit mode is
ideal.
Bernd
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