CODEWITHSUNDEEP
cassandra
Funzo
Funzo

Reputation: 1290

Select From Cassandra with Order By and Include position in order by

I have a table in cassandra which has the following structure

CREATE TABLE example (session text, seq_number int, Primary key((session), seq_num))

In the data I would expect all sequence numbers to be in the table starting at 0.

So a table might look like 

session text| seq_number|
  session1  | 0         |
  session1  | 1         |
  session1  | 2         |
  session1  | 4         |   // bad row, means missing data

In this example I would like to read only the first 3 rows. I don't want the fourth row because it is not 3 and it is at index 3. Is this possible?

Upvotes: 1

Views: 27

Answers (1)

Chris Lohfink
Chris Lohfink

Reputation: 16400

Possible yes, you can use group by on session and a user defined aggregation function. It may be more work than its worth though, if you just set fetch size low (say 100) on queries then iterate through resultset on client side it might save you a lotta work and potentially even be more efficient overall. I would recommend implementing the client side solution first and benchmarking it to see if its even necessary or beneficial.

Upvotes: 3

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