Subject | Re: [firebird-support] Re: locking a database |
---|---|
Author | Ann W. Harrison |
Post date | 2006-05-16T16:33:11Z |
martinknappe wrote:
multiple users to change the same data at the same time without
stepping on each other. If two updates conflict, one will get
an error.
transaction can change the same record (update or delete) until
your transaction completes. That's true of all multi-user
databases. Different databases handle the problem in different
ways - Firebird creates multiple versions of records so a reader
can continue to see the old version while writers create new
versions. If there's a new version of a record that your
transaction can't read, you can't change that record. There's no
configuration required.
databases - they're an interesting subject.
Regards,
Ann
>> i'm new to firebird and databases in general ...No. That's one of the reasons databases exist - they allow
> i was only thinking that if you have several write-authorised users
> simultaneously connected to a database and user 1 for instance
> modifies an entry in transaction 1 while user 2 deletes the exact same
> entry in transaction 2, you would end up with inconsistent data..
multiple users to change the same data at the same time without
stepping on each other. If two updates conflict, one will get
an error.
>If you change a record (insert, update, or delete), no other
> so, in the course of one transacition, all other transactions are
> blocked from modifying by default or do i have to configure that
> myself? if so, is it a server-wide configuration that applies for all
> registered databases or do i have to configure that (e.g. via isql)
> for each and every database?
transaction can change the same record (update or delete) until
your transaction completes. That's true of all multi-user
databases. Different databases handle the problem in different
ways - Firebird creates multiple versions of records so a reader
can continue to see the old version while writers create new
versions. If there's a new version of a record that your
transaction can't read, you can't change that record. There's no
configuration required.
> i'm working on a database app for my college degree and for now i'mThere's nothing to worry about, but you might pick up a book on
> still doing everything (client-app and firebird) on my own machine but
> it's all supposed to be ported at the end to client-server and i was
> starting to worry about how this all behaves when multiple clients are
> connected to one database on a remote host...
databases - they're an interesting subject.
Regards,
Ann