cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Eric Evans (JIRA)" <j...@apache.org>
Subject [jira] Commented: (CASSANDRA-2025) generalized way of expressing hierarchical values
Date Tue, 25 Jan 2011 16:10:49 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-2025?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12986474#action_12986474
] 

Eric Evans commented on CASSANDRA-2025:
---------------------------------------

FTR. I think I'm good with either colon {{:}} or slash {{/}}, both seem future-proof, and
I'm not sure one is more or less readable to my eyes.

> generalized way of expressing hierarchical values
> -------------------------------------------------
>
>                 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
>
>   Original Estimate: 0h
>  Remaining Estimate: 0h
>
> 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}
> Or in the case of composite column names:
> {code:style=SQL}
> SELECT columnA:columnB,column1:column2 FROM Standard2 USING CONSISTENCY.QUORUM WHERE
KEY = key;
> UPDATE Standard2 SET columnA:columnB = valueC, column1:column2 = value3 WHERE KEY = key;
> {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?
> *Edit: improved final example*
> *Edit: restore final example, create new one (gah).*

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message