Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
Home -> Community -> Usenet -> c.d.o.server -> Re: oracle - mysql comparison
VC wrote:
> Hello Daniel,
>
> "Daniel Morgan" <damorgan_at_x.washington.edu> wrote in message
> news:1089945278.134355_at_yasure...
>
>>VC wrote: >> >> >>>A correct concurrency control/model ensures that all the permitted >>>transactions are serializable. In this sense, databases like DB2 or
>>>implement a correct concurrency model albeit at the expense of lower >>>concurrency in some circumstances. Funnily enough, none of the Oracle >>>isolation levels can make the same promise, i.e. ensure serializable >>>transaction histories, in any of its isolation levels. Usually, it's
>>>easy to obtain correct results by augmenting an isolation level with >>>something like 'select for update', though.. >> >>And if this is true why, exactly, would anyone care at the expense of >>being able to extract an accurate answer from a database without >>performing table locks on all resources? >>
My point is that in all of the other databases to which you have referred it is impossible to get a result set consistent to a point-in-time without locking the resources (not at the row level but at the table level).
Something I would think far more important than anything you brought up.
In Oracle this can be achieved without any locking.
Daniel Morgan Received on Fri Jul 16 2004 - 20:20:27 CDT