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https://issues.apache.org/jira/browse/CASSANDRA-2474?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13172604#comment-13172604
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Jonathan Ellis edited comment on CASSANDRA-2474 at 12/19/11 8:59 PM:
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The crucial part of this latest proposal is that it really highlights that
transposition really is just an implementation detail from the relational
perspective. So, to flesh that out:
{code}
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('tjefferson', '1818', 'jadams', 'Revolution was effected before the war
commenced');
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('tjefferson', '1763', 'jadams', 'Democracy will soon degenerate into an
anarchy');
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('tjefferson', '1790', 'gwashington', 'To be prepared for war is one of
the most effectual means of preserving peace');
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('bfranklin', '1781', 'tjefferson', 'Every government degenerates when
trusted to the rulers of the people alone');
{code}
... corresponding to the data in !2474-transposed-1.PNG!
which in "raw" form looks like !2474-transposed-raw.PNG!
Does that make sense? We're using TRANSPOSED AS similarly to how databases
have used storage hints like CLUSTERED. It doesn't affect the relational model
of the data, but it gives you different performance characteristics. (The
analogy is particularly apt in that both CLUSTERED and TRANSPOSED AS affect
ordering of results.)
was (Author: jbellis):
The crucial part of this latest proposal is that it really highlights that
transposition really is just an implementation detail from the relational
perspective. So, to flesh that out:
{code}
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('tjefferson', '1818', 'jadams', 'Revolution was effected before the war
commenced');
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('tjefferson', '1763', 'jadams', 'Democracy will soon degenerate into an
anarchy');
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('tjefferson', '1790', 'gwashington', 'To be prepared for war is one of
the most effectual means of preserving peace');
INSERT INTO timeline (user_id, posted_at, posted_by, body)
VALUES ('bfranklin', '1781', 'tjefferson', 'Every government degenerates when
trusted to the rulers of the people alone');
{code}
... corresponding to the data in !2474-transposed-1.PNG!, which in "raw" form
looks like !2474-transposed-raw.PNG!
Does that make sense? We're using TRANSPOSED AS similarly to how databases
have used storage hints like CLUSTERED. It doesn't affect the relational model
of the data, but it gives you different performance characteristics. (The
analogy is particularly apt in that both CLUSTERED and TRANSPOSED AS affect
ordering of results.)
> CQL support for compound columns
> --------------------------------
>
> Key: CASSANDRA-2474
> URL: https://issues.apache.org/jira/browse/CASSANDRA-2474
> Project: Cassandra
> Issue Type: New Feature
> Components: API, Core
> Reporter: Eric Evans
> Assignee: Pavel Yaskevich
> Labels: cql
> Fix For: 1.1
>
> Attachments: 2474-transposed-1.PNG, 2474-transposed-raw.PNG,
> screenshot-1.jpg, screenshot-2.jpg
>
>
> For the most part, this boils down to supporting the specification of
> compound column names (the CQL syntax is colon-delimted terms), and then
> teaching the decoders (drivers) to create structures from the results.
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