Re: [ib-support] About Atomicity, Consistency, Isolation, and Durability
Pirtea Calin Iancu
----- Original Message -----
From: "Ann W. Harrison"
> Firebird transactions are atomic. They succeed or fail as
> a group. They are durable - all changes are written out
> when a transaction commits. Those two properties are well
> defined. Isolation and consistency are more open topics
> and are related. The InterBase/Firebird concurrency transaction
> mode is consistent - they have an unchanging view of data.
> Read-committed mode is available for those who prefer to give
> up consistency in favor of always seeing the most current
> committed version of data.
> The SQL standard describes several levels of isolation -
> serializable being the highest level. No database that I
> know of, commercial or open source, provides serializable
> transactions by default. Firebird has a mode in which it
> provides serializable transactions - deadlock free. That
> is not its normal mode of operation. The normal mode meets
> or exceeds the requirements of the three lower isolation
> So, yes, despite the rumors to the contrary, Interbase/
> Firebird do provide ACID transactions.
Thanks for the information. I was right to think that the
information I found was false.