Michaël Figuière created CASSANDRA-8878:
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             Summary: Counter Tables should be more clearly identified
                 Key: CASSANDRA-8878
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8878
             Project: Cassandra
          Issue Type: Improvement
            Reporter: Michaël Figuière
            Priority: Minor


Counter tables are internally considered as a particular kind of table, 
different from the regular ones. This counter specific nature is implicitly 
defined by the fact that columns within a table have the {{counter}} data type. 
This nature turns out to be persistent over the time, that is if the user do 
the following:

{code}
CREATE TABLE counttable (key uuid primary key, count counter);
ALTER TABLE counttable DROP count;
ALTER TABLE counttable ADD count2 int;
{code} 

The following error will be thrown:

{code}
Cannot add a non counter column (count2) in a counter column family
{code}

Even if the table doesn't have any counter column anymore. This implicit, 
persistent nature can be challenging to understand for users (and impossible to 
infer in the case above). For this reason a more explicit declaration of 
counter tables would be appropriate, as:

{code}
CREATE COUNTER TABLE counttable (key uuid primary key, count counter);
{code}

Besides that, adding a boolean {{counter_table}} column in the 
{{system.schema_columnfamilies}} table would allow external tools to easily 
differentiate a counter table from a regular one.



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