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https://issues.apache.org/jira/browse/CASSANDRA-5622?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13677593#comment-13677593
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Jonathan Ellis edited comment on CASSANDRA-5622 at 6/6/13 10:16 PM:
--------------------------------------------------------------------
Two solutions suggest themselves:
# Embrace ignoring of K and just pass new Object()
# Treat K as designed and accept responsibility for generating appropriate bind
variables
I'm not a huge fan of #1 since it forces the user to do more work to generate
bind variables for the PK values. I'd rather automate that.
Let me give an example of what I mean in #2. Suppose we have word counts as
follows:
{code}
CREATE TABLE word_counts (
file_name text,
counted_at timestamp,
word text,
count int,
PRIMARY KEY ((file_name, counted_at), word)
);
{code}
Then the user would configure CQL such as "UPDATE word_counts SET count = ?".
CqlRW would inspect the table definition and realize it needs to add " WHERE
file_name = ? AND counted_at = ? AND word = ?".
Then when it gets a Map<String, BB> as K, it combines those with the List<BB>
variables. It knows the ordering of the pk columns since it generated it
itself.
One downside: this doesn't lend itself to INSERT statements, since that does
not separate SET/WHERE the way UPDATE does. This is a limitation I can live
with.
was (Author: jbellis):
Two solutions suggest themselves:
# Embrace ignoring of K and just pass new Object()
# Treat K as designed and accept responsibility for generating appropriate bind
variables
I'm not a huge fan of #1 since it forces the user to do more work to generate
bind variables for the PK values. I'd rather automate that.
Let me give an example of what I mean in #2. Suppose we have word counts as
follows:
{code}
CREATE TABLE word_counts (
file_name text,
counted_at timestamp,
word text,
count int,
PRIMARY KEY ((file_name, counted_at), word)
);
{code}
Then the user would configuer CQL such as "UPDATE word_counts SET count = ?".
CqlRW would inspect the table definition and realize it needs to add " WHERE
file_name = ? AND counted_at = ? AND word = ?".
Then when it gets a Map<String, BB> as K, it combines those with the List<BB>
variables. It knows the ordering of the pk columns since it generated it
itself.
One downside: this doesn't lend itself to INSERT statements, since that does
not separate SET/WHERE the way UPDATE does. This is a limitation I can live
with.
> Update CqlRecordWriter to conform to RecordWriter API
> -----------------------------------------------------
>
> Key: CASSANDRA-5622
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5622
> Project: Cassandra
> Issue Type: Bug
> Affects Versions: 1.2.6
> Reporter: Jonathan Ellis
> Assignee: Alex Liu
> Fix For: 1.2.6
>
>
> {{RecordWriter<K, V>}} is supposed to write values V that can be uniquely
> identified by keys K.
> Currently CqlRW requires the user to give it all the bind variables for a
> complete statement in V, and effectively ignores K.
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