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POUsing Cassandra and CQL3, how do you insert an entire wide row in a single request?
 

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  1. POUsing Cassandra and CQL3, how do you insert an entire wide row in a single request?
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    <p>I want to insert a single row with 50,000 columns into Cassandra 1.2.8. Before inserting, I have all the data for the entire row ready to go (in memory):</p> <pre><code>+---------+------+------+------+------+-------+ | | 0 | 1 | 2 | ... | 49999 | | row_id +------+------+------+------+-------+ | | text | text | text | ... | text | +---------+------+------+------|------+-------+ </code></pre> <p>The column names are integers, allowing slicing for pagination. The column values are a value at that particular index.</p> <p>CQL3 table definition:</p> <pre><code>create table results ( row_id text, index int, value text, primary key (row_id, index) ) with compact storage; </code></pre> <p>As I already have the row_id and all 50,000 name/value pairs in memory, I just want to insert a single row into Cassandra in a single request/operation so it is as fast as possible.</p> <p>The only thing I can seem to find is to do execute the following 50,000 times:</p> <pre><code>INSERT INTO results (row_id, index, value) values (my_row_id, ?, ?); </code></pre> <p>the first <code>?</code> is is an index counter (<code>i</code>) and the second <code>?</code> is the text value to store at location <code>i</code>.</p> <p>This takes a lot of time. Even when we put the above INSERTs into a batch, it takes a lot of time.</p> <p>We have all the data we need (the complete row) in its entirety, I would assume it to be very easy to just say "here, Cassandra, store this data as a single row in one request", for example:</p> <pre><code>//EXAMPLE-BUT-INVALID CQL3 SYNTAX: insert into results (row_id, (index,value)) values ((0,text0), (1,text1), (2,text2), ..., (N,textN)); </code></pre> <p>This example isn't possible via current CQL3 syntax, but I hope it illustrates the desired effect: everything would be inserted as a single query.</p> <p>Is it possible to do this in CQL3 and the DataStax Java Driver? If not, I suppose I'll be forced to use Hector or the Astyanax driver and the Thrift <code>batch_insert</code> operation instead?</p>
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    1. USLes Hazlewood
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    1. COHave you tried using lists / sets / maps. For this case it should do the trick but, as Alex says, it would make an interesting addition to CQL3.
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    2. COYes, we have tried, and it was reasonably fast, but it completely breaks the desired data model: you cannot do slice queries on CQL3 collections.
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