generalized way of expressing hierarchical values
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                 Key: CASSANDRA-2025
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-2025
             Project: Cassandra
          Issue Type: Sub-task
          Components: API
            Reporter: Eric Evans
            Assignee: Eric Evans
            Priority: Minor
             Fix For: 0.8


While hashing out {{CREATE KEYSPACE}}, it became obvious that we needed a 
syntax for expressing hierarchical values.  Properties like 
{{replication_factor}} can be expressed simply using keyword arguments like 
({{replication_factor = 3}}), but {{strategy_options}} is a map of strings.

The solution I took in CASSANDRA-1709 was to dot-delimit "map name" and option 
key, so for example:

{code:style=SQL}
CREATE KEYSPACE keyspace WITH ... AND strategy_options.DC1 = "1" ...
{code}

This led me to wonder if this was a general enough approach for any future 
cases that might come up.  One example might be compound/composite column 
names.  Dot-delimiting is a bad choice here since it rules out ever introducing 
a float literal.

One suggestion would be to colon-delimit, so for example:

{code:style=SQL}
CREATE KEYSPACE keyspace WITH ... AND strategy_options:DC1 = "1" ...
{code}

As an aside, this also led me to the conclusion that {{CONSISTENCY.<LEVEL>}} is 
probably a bad choice for consistency level specification.  It mirrors the 
underlying enum for no good reason and should probably be changed to 
{{CONSISTENCY <LEVEL>}} (i.e. omitting the separator).  For example:

{code:style=SQL}
SELECT column FROM Standard2 USING CONSISTENCY QUORUM WHERE KEY = key;
{code}

Thoughts?

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