I can't find much on the topic of dummy partition keys in Cassandra, but what I can find tends to the idea that you should avoid them at all. By dummy, I mean a column whose sole purpose is to contain the same value for all rows, thereby putting all the data in 1 node and providing the lowest possible power. For example:
dummy | id | name
-------------------------
0 | 01 | 'Oliver'
0 | 02 | 'James'
0 | 03 | 'Nicholls'
Two key points regarding why you should avoid dummy partition keys:
1) As a result, you get the data "hot spots". There is a lot of data stored on 1 node, so there will be more traffic than node, and you have a poor distribution over the cluster.
2) The final partition space. If you put all the data in one partition, it will ultimately not be able to store more data.
I can understand these points, and I agree that you definitely want to avoid such situations, so I put this idea out of my head and tried to come up with a good section key for my table. The table in question stores sites, and there are two general ways in which the table is queried in our system. Either one site is requested, or all sites are requested.
This puts me in an awkward position, because the table is either requested for nothing, or on the site identifier, and in creating a unique field, the section key gives me very high power and high latency for requests requesting all sites.
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