[erlang-questions] replicated mnesia write operations

[Håkan Mattsson]

On Mon, Sep 28, 2009 at 4:39 PM, Roberto Ostinelli
<roberto.ostinelli@REDACTED> wrote:
> dear all,
>
> let's say that i have a mnesia database on node 1, which has a
> disc_copy on node 2.
>
> +--------------+    +--------------+
> | db disc_copy |____| db disc_copy |
> | node 1       |    | node 2       |
> +--------------+    +--------------+
>
> i would like the following:
>
> * WRITE operations on node 1 get propagated to (pretty standard behaviour):
>   . disc and ram on node 1
>   . disc and ram on node 2
>
> * WRITE operations on node 2 get ONLY propagated to:
>   . ram on node 2
>
> i.e. i would like that write operations on node 2 do not get
> propagated to node 1, nor to the disc of node 2.

Why do you want such a setup?

> is this possible?

Not with full transaction support on both nodes.
You can however write directly in the ets tables on node 2.
See mnesia:activity/4.

/Håkan
---
Håkan Mattsson (uabhams)
Erlang/OTP, Ericsson AB