If you can construct unique primary keys from the data you have, I'd suggest
you create your own custom primary keys instead of using UUIDs. It will be
easier for you to retrieve the records.
If you use UUIDs as your primary keys for a table, you need to have some kind
of index so that you can get those UUIDs based on, say user's emails, in your
first query and then be able to use those UUIDs in subsequent queries.
On Monday, November 23, 2015 10:50 AM, Jack Krupansky
<[email protected]> wrote:
The point is to have a unique, generated ID for each entity, to ensure
absolute uniqueness. In the old days each app had its own technique for
generating unique IDs. Now we have UUIDs, which are unique, but are generated
uniformly across systems and applications. Uniqueness is guaranteed even if an
account is closed and reopened. Email addresses and user IDs (user-assigned)
can of course be reused.
You could also have an application-generated account number and use that as the
unique key, with user ID, user name, and email as alternate keys.
-- Jack Krupansky
On Mon, Nov 23, 2015 at 11:31 AM, Prem Yadav <[email protected]> wrote:
OK.My question is more about what are the use case of any table uuid as
partition key. Will appreciate inputs from others.
Thanks,Prem
On Mon, Nov 23, 2015 at 4:25 PM, Jay Reddy <[email protected]> wrote:
Hi Prem,
We have two tables, one with email id as partition key and other with
userid(uuid).Please refer to www.killrvideo.com website. It is a great place to
understand how a web application is built on Cassandra.
Thanks,Jay
On Mon, Nov 23, 2015 at 11:18 AM, Prem Yadav <[email protected]> wrote:
Thanks Jay. Now this is great while creating the user. How does the user change
the details? let's say email id or password? How do you lookup the user table?
On Mon, Nov 23, 2015 at 4:14 PM, Jay Reddy <[email protected]> wrote:
Here is one use case ..
We are designing a web application using Cassandra. When a user signs on we
create user info in user table with userid (uuid) is primary and is responded
back to UI.
UI uses this UUID for any future communications. UI can also get user id when
searched for an user detail in "search" (achieved by Solr).
Thanks,Jay
On Mon, Nov 23, 2015 at 11:08 AM, Prem Yadav <[email protected]> wrote:
Hi,
I am trying to understand different use cases related to using UUID as the
partition key. I am sure I am missing something trivial and will be grateful
and you can help me understand this.
When do you use the UUID as the primary key? What can be a use case?Since it is
unique, how do you query it?
Let's take a user table with UUID as primary key.
create table user (id uuid primary key, name varchar,company varchar,country
varchar);
Now I can write to the table using the uuid() function to generate the uid. But
how do you query it?The only use case I see is create a secondary index and use
that for querying.
Am I missing something here?
Thanks,Prem
