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https://issues.apache.org/jira/browse/BEAM-6324?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16804605#comment-16804605
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Shahar Frank commented on BEAM-6324:
------------------------------------
The PR introduces a problem IMHO:
The code:
{code:java}
p.apply(CassandraIO.<Table1>read().withHosts(Arrays.asList(config.cassandraHosts()))
.withPort(config.cassandraPort()).withEntity(Table1.class).withCoder(SerializableCoder.of(Table1.class))
.withKeyspace(config.cassandraKeyspace())
.withTable(config.cassandraTable1())
.withQuery(String.format("select * from %s.%s where
data='Whether'",
config.cassandraKeyspace(),
config.cassandraTable1())))
{code}
Will not work if the 'withKeyspace' line is commented:
{code:java}
Exception in thread "main" java.lang.IllegalArgumentException: withKeyspace()
is required
at
org.apache.beam.vendor.guava.v20_0.com.google.common.base.Preconditions.checkArgument(Preconditions.java:122)
at
org.apache.beam.sdk.io.cassandra.CassandraIO$Read.expand(CassandraIO.java:323)
at
org.apache.beam.sdk.io.cassandra.CassandraIO$Read.expand(CassandraIO.java:132)
at org.apache.beam.sdk.Pipeline.applyInternal(Pipeline.java:537)
at org.apache.beam.sdk.Pipeline.applyTransform(Pipeline.java:471)
at org.apache.beam.sdk.values.PBegin.apply(PBegin.java:44)
at org.apache.beam.sdk.Pipeline.apply(Pipeline.java:167)
at org.apache.beam.examples.ReadCassandra.main(ReadCassandra.java:16)
{code}
Nor with 'withTable ' commented:
{code:java}
Exception in thread "main" java.lang.IllegalArgumentException: withTable() is
required
at
org.apache.beam.vendor.guava.v20_0.com.google.common.base.Preconditions.checkArgument(Preconditions.java:122)
at
org.apache.beam.sdk.io.cassandra.CassandraIO$Read.expand(CassandraIO.java:324)
at
org.apache.beam.sdk.io.cassandra.CassandraIO$Read.expand(CassandraIO.java:132)
at org.apache.beam.sdk.Pipeline.applyInternal(Pipeline.java:537)
at org.apache.beam.sdk.Pipeline.applyTransform(Pipeline.java:471)
at org.apache.beam.sdk.values.PBegin.apply(PBegin.java:44)
at org.apache.beam.sdk.Pipeline.apply(Pipeline.java:167)
at org.apache.beam.examples.ReadCassandra.main(ReadCassandra.java:16)
{code}
I think this redundancy may lead to many user errors. E.g. what happens if the
input to `withTable` is not the same as the table used within the query?
WDYT?
> CassandraIO.Read - Add the ability to provide a filter to the query
> -------------------------------------------------------------------
>
> Key: BEAM-6324
> URL: https://issues.apache.org/jira/browse/BEAM-6324
> Project: Beam
> Issue Type: Improvement
> Components: io-java-cassandra
> Reporter: Shahar Frank
> Assignee: Shahar Frank
> Priority: Major
> Labels: performance, pull-request-available, triaged
> Fix For: Not applicable
>
> Time Spent: 12h 50m
> Remaining Estimate: 0h
>
> CassandraIO.Read doesn't support using WHERE to filter the input at the
> source (In Cassandra) which might provide great performance boost.
> Already implemented by:
> https://github.com/apache/beam/pull/7340
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