Reading the most recent updated row in cassandra

Question

I have a use case and want suggestion on the below.

Structure :

            Rowkey_1: 

                       Column1 = value1;
                       Column2 = value2;
            Rowkey_2: 

                       Column1 = value1;
                       Column2 = value2;

" Suppose i am writing 1000 rows into cassandra with each row having couple of columns. After sometime i update only 100 rows and make changes for column values ".

-> when i read data from cassandra i only want to get these 100 updated rows and not the entire row key information.

Is there a way to say to cassandra like give me all row keys from start - > end where time in between "Time_start" to "Time_end"

in SQL Lingo -- > select from "" to "" where time between "time_start" and "time_end".

P.S. i read Basic Time Series with Cassandra where it says you can annotate rowkey like the below Inserting data — {:key => ‘server1-load-20110306′, :column_name => TimeUUID(now), :column_value => 0.75}

Here the column family has TimeUUID columns.

My question is can you annotate you rowkey with date and time like this : { :key ==> 2012-11-18 16:00:15 }

OR any other way to get only the recent updated rows.

Any suggestion/ guidance really appreciated.

rs_atl rs_atl · Accepted Answer · 2012-11-21T18:23:51

You can't do range queries on keys unless you use ByteOrderedPartitioner, which you shouldn't use. The way to do this is by writing known sentinel values as keys, such as a timestamp representing the beginning of the day. Then you can do the column slice by time.

Reading the most recent updated row in cassandra

1 Answers