On Tue, 21 Mar 2000, Richard Hayes wrote:
> MySQL is small, fast and stable. But it is not a full blown database
> system such as IBM DB2 etc
>
> It can not do 'rollbacks' but since neither can the the web, who
> cares???
Great logic there. It can not do 'rollbacks' but since neither can
<insert irrelevant item>, who cares??
Rollbacks are required for several reasons, two important ones
being the following:
(1) if a lengthy transaction-based process (which is possible from ONE
single, stateless web hit) fails partway through, it is quite messy
to undo what has been done so far without rollback.
(2) in a multi-tasking environment (which is common with MANY stateless
single web hits occurring simultaneously), a complete transaction
must be commited as an atomic unit, otherwise, interference from
other 'piecemeal' transaction bits can cause confusion and
database inconsistencies, e.g. see the example posted on this
thread yesterday regarding auto-incrementing keys/fields.
I've been contemplating implementing a rollback and commit
feature for MySQL using some perl classes, but it'll be Alotta Verk.
And it will never reach the efficiency of a DBMS that provides
this feature, since table-wide locking will probably be required.
-rickw
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Rick Welykochy || Praxis Services
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