Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Re: oracle - mysql comparison

Re: oracle - mysql comparison

From: Five Cats <cats_spam_at_[127.0.0.1>
Date: Wed, 14 Jul 2004 21:43:22 +0100
Message-ID: <H9J013IqrZ9AFwh6@[127.0.0.1]>


In message <336da121.0407141111.67a9ab79_at_posting.google.com>, Alex Filonov <afilonov_at_yahoo.com> writes
>"VC" <boston103_at_hotmail.com> wrote in message
>news:<KbZIc.81643$Oq2.30187_at_attbi_s52>...
>> Hello,
>>
>> Please see in-line:
>>
>> "Alex Filonov" <afilonov_at_yahoo.com> wrote in message
>> news:336da121.0407131327.363b8e5a_at_posting.google.com...
>> > As for consistency (I suppose you mean read-only), it's implemented in
>> > ProgreSQL, another Open Source DB engine. BTW, other commercial RMBDS
>> > (DB2, MSSQL) don't have read-only consistency and sell pretty well at
>> that.
>>
>> Please define 'read-only consistency' and elaborate a bit on why DB2 and
>> MSSQL don't have it.
>>
>
>Read-only consistency is defined well enough in Oracle Concepts document.
>In short, it means that result of any query reflects commited data in the
>tables as of time when the query was submitted, without locking any objects
>in the database (readers don't block writers, writers don't block readers).
>
>DB2 and MSSQL can do either dirty read (including uncommited changes) or
>consistent read with lock (read commited). To my knowledge, only PostgreSQL
>and Interbase have read-only consistency in Oracle definition.

So does Informix IDS, so long as you specify the correct isolation level.

>
>As for why... I don't work (and never did) for either IBM or M$, so I
>don't have an answer to this question.

-- 
Five Cats
Email to: cats_spam at uk2 dot net
Received on Wed Jul 14 2004 - 15:43:22 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US