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POCassandra createSliceQuery clarification
 

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  1. POCassandra createSliceQuery clarification
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    <p>I'm trying to retrieve all columns of a row in Cassandra using Thrift 1.0 lib. I found some examples by Googling , in particular:</p> <pre><code>SliceQuery&lt;String, String, String&gt; sliceQuery = hectorTemplate.createSliceQuery( StringSerializer.get(), StringSerializer.get(), StringSerializer.get()); sliceQuery.setColumnFamily("myname"); sliceQuery.setKey("myid"); sliceQuery.setRange(null, null, false, 20); QueryResult&lt;ColumnSlice&lt;String,String&gt;&gt; queryResult = sliceQuery.execute(); ColumnSlice&lt;String,String&gt; slice = queryResult.get(); List&lt;HColumn&lt;String, String&gt;&gt; retrievedColumns = slice.getColumns(); for (HColumn&lt;String, String&gt; column : retrievedColumns) { System.out.println(column.getName() +"::"+ column.getValue()); } </code></pre> <p>However, I could not find any information on what those parameters and types in Hector objects are?? </p> <p>For example, here: </p> <pre><code>SliceQuery&lt;String, String, String&gt; </code></pre> <ul> <li>all types here are String - what are they types of? Column name type? column value types? </li> </ul> <p>Then, we specify parameters to the createSliceQuery(): </p> <pre><code>hectorTemplate.createSliceQuery( StringSerializer.get(), StringSerializer.get(), StringSerializer.get()); </code></pre> <p>Again - what are those serializers for? why are there only 3 serializers - is if for the first and last column, and something else? What if I get many columns, how do I specify serializers for them?</p> <p>Then, we retrieve </p> <pre><code>List&lt;HColumn&lt;String, String&gt;&gt; </code></pre> <p>-- again, what are these String types for? If I have a column of type BytesType - where do I specify that?</p> <p>If there are some decent API docs (not just method signatures with no explanation of what their parameters are) - could you point me to them?</p> <p>thanks! Marina</p>
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    1. This table or related slice is empty.
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    1. USTyler Hobbs
    1. USMarina
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    1. This table or related slice is empty.
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    1. This table or related slice is empty.
    1. COohhhhh.. hold on. hold on please. can you ask one question at a time? Rather select an API, may be astyanax, hector, native binary driver or pelops and can ask question based on them?
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      1. POCassandra createSliceQuery clarification
      1. USabhi
    2. COThis is a good question about the Hector API (I don't understand why it is not clear to you which API is in question). Indeed, the Hector javadoc does not seem to document the generic types.
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      1. USTom
    3. COFor what it's worth, have a look at Pelops. It's an excellently designed and documented Cassandra client library. I never understood why most people go for Hector.
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      1. USTom
 

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