volunteer wanted to write a few FAQ entries about Mnesia

[Chandrashekhar Mullaparthi]

mnesia:match_object 
mnesia:select 

achieve this, but you are right, there is no explicit concept of aggregate
keys.

Chandru

-----Original Message-----
From: Chris Pressey [mailto:cpressey@REDACTED]
Sent: 21 February 2003 22:05
To: Ulf Wiger
Cc: matthias@REDACTED; erlang-questions@REDACTED
Subject: Re: volunteer wanted to write a few FAQ entries about Mnesia


On Fri, 21 Feb 2003 11:53:02 +0100 (MET)
Ulf Wiger <etxuwig@REDACTED> wrote:

> On Thu, 20 Feb 2003, Chris Pressey wrote:
> 
> >Records are accessed by a single key (which may be unique
> >or duplicate) and there is no concept of a secondary key.
> 
> Actually there is. You can define an index on a non-key
> attribute, and access records using mnesia:index_read/3 or
> index_match_object/2.

Oops!  I meant there is no concept of an aggregate key, i.e. of using
multiple fields to identify a record.

-Chris



 NOTICE AND DISCLAIMER:
This email (including attachments) is confidential.  If you have received
this email in error please notify the sender immediately and delete this
email from your system without copying or disseminating it or placing any
reliance upon its contents.  We cannot accept liability for any breaches of
confidence arising through use of email.  Any opinions expressed in this
email (including attachments) are those of the author and do not necessarily
reflect our opinions.  We will not accept responsibility for any commitments
made by our employees outside the scope of our business.  We do not warrant
the accuracy or completeness of such information.