Sylvain Lebresne created CASSANDRA-5702:
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             Summary: ALTER RENAME is broken in trunk
                 Key: CASSANDRA-5702
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5702
             Project: Cassandra
          Issue Type: Bug
            Reporter: Sylvain Lebresne
            Assignee: Sylvain Lebresne
             Fix For: 2.0 beta 1


CASSANDRA-5125 has broken {{ALTER RENAME}} when the column is a default alias 
(for thrift column families where the PK columns haven't been renamed yet).

The problem is basically that while we assign default aliases to PK columns 
when they don't have one, we currently "fake" those default aliases and do not 
persist them. Concretely, CFDefinition is aware of them, but CFMetaData is not, 
which break renaming post CASSANDRA-5125.

We could fix rename punctually, but there is another related problem: for the 
same reason, if you try to create an index on a column that is a non-renamed 
default alias, this doesn't work with the arguably confusing message "No column 
definition found for column X". Here again, we could fix it punctually, but it 
starts to sound like we need a more general fix.

So I suggest stopping to "fake" those default aliases, but instead to just 
create "real" aliases (that are known of CFMetaData and persisted in the 
schema) when there is none. After all, from a user point of view, why should a 
default column name be any special. And on top of fixing the issues above, this 
also:
# fix CASSANDRA-5489 in a somewhat simpler way
# makes it easier for clients reading the schema CFs. They won't to infer the 
default aliases anymore.

The only theoretical downside is that we lose the information that a given CQL3 
column name is one assigned by default versus one set up by the user, but given 
the user can rename those column names anyway, not sure this matters in any way.


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