I just used 'synthetic key' as it's a term used with standard rdbms to
mean a key that means nothing in the model, and is often a sequence or such.
There's nothing particular to cassandra specific to that term. Just
thought it would be something familiar to someone who understood rdbms.
On 05/04/2013 02:44 PM, Jabbar Azam wrote:
I never thought about using a synthetic key, but in this instance with
about a dozen rows it's probably ok. Thanks for your great idea.
Where did you read about the synthetic key idea? I've not come across
it before.
Thanks
Jabbar Azam
On 4 May 2013 19:30, Dave Brosius <dbros...@mebigfatguy.com
<mailto:dbros...@mebigfatguy.com>> wrote:
if you want to store all the roles in one row, you can do
create table roles (synthetic_key int, name text, primary
key(synthetic_key, name)) with compact storage
when inserting roles, just use the same key
insert into roles (synthetic_key, name) values (0, 'Programmer');
insert into roles (synthetic_key, name) values (0, 'Tester');
and use
select * from roles where synthetic_key = 0;
(or some arbitrary key value you decide to use)
the that data is stored on one node (and its replicas)
of course if the number of roles grows to be large, you lose most
of the value in having a cluster.
On 05/04/2013 12:09 PM, Jabbar Azam wrote:
Hello,
I want to create a simple table holding user roles e.g.
create table roles (
name text,
primary key(name)
);
If I want to get a list of roles for some admin tool I can use
the following CQL3
select * from roles;
When a new name is added it will be stored on a different host
and doing a select * is going to be inefficient because the
table will be stored across the cluster and each node will
respond. The number of roles may be less than or just greater
than a dozen. I'm not sure if I'm storing the roles correctly.
The other thing I'm thinking about is that when I've read the
roles once then I can cache them.
Thanks
Jabbar Azam
