Updated Branches: refs/heads/cassandra-1.1 5dac2086d -> 3a4459f0a
Merge from 1.0 Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/3a4459f0 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/3a4459f0 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/3a4459f0 Branch: refs/heads/cassandra-1.1 Commit: 3a4459f0a69d361c3c3480d7cb8b0188aef7700f Parents: 5dac208 f2a4309 Author: Brandon Williams <brandonwilli...@apache.org> Authored: Tue Feb 14 14:19:47 2012 -0600 Committer: Brandon Williams <brandonwilli...@apache.org> Committed: Tue Feb 14 14:19:47 2012 -0600 ---------------------------------------------------------------------- examples/pig/README.txt | 6 ++++-- examples/pig/example-script.pig | 4 ++-- 2 files changed, 6 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/3a4459f0/examples/pig/README.txt ---------------------------------------------------------------------- diff --cc examples/pig/README.txt index aea0a77,0000000..3bdbf10 mode 100644,000000..100644 --- a/examples/pig/README.txt +++ b/examples/pig/README.txt @@@ -1,70 -1,0 +1,72 @@@ +A Pig storage class that reads all columns from a given ColumnFamily, or writes +properly formatted results into a ColumnFamily. + +Setup: + +First build and start a Cassandra server with the default +configuration and set the PIG_HOME and JAVA_HOME environment +variables to the location of a Pig >= 0.7.0 install and your Java +install. + +If you would like to run using the Hadoop backend, you should +also set PIG_CONF_DIR to the location of your Hadoop config. + +Finally, set the following as environment variables (uppercase, +underscored), or as Hadoop configuration variables (lowercase, dotted): +* PIG_INITIAL_ADDRESS or cassandra.thrift.address : initial address to connect to +* PIG_RPC_PORT or cassandra.thrift.port : the port thrift is listening on +* PIG_PARTITIONER or cassandra.partitioner.class : cluster partitioner + +For example, against a local node with the default settings, you'd use: +export PIG_INITIAL_ADDRESS=localhost +export PIG_RPC_PORT=9160 +export PIG_PARTITIONER=org.apache.cassandra.dht.RandomPartitioner + +These properties can be overridden with the following if you use different clusters +for input and output: +* PIG_INPUT_INITIAL_ADDRESS : initial address to connect to for reading +* PIG_INPUT_RPC_PORT : the port thrift is listening on for reading +* PIG_INPUT_PARTITIONER : cluster partitioner for reading +* PIG_OUTPUT_INITIAL_ADDRESS : initial address to connect to for writing +* PIG_OUTPUT_RPC_PORT : the port thrift is listening on for writing +* PIG_OUTPUT_PARTITIONER : cluster partitioner for writing + + +Then you can run it like this: + +examples/pig$ bin/pig_cassandra -x local example-script.pig + +This will run the test script against your Cassandra instance +and will assume that there is a MyKeyspace/MyColumnFamily with some +data in it. It will run in local mode (see pig docs for more info). + +If you'd like to get to a 'grunt>' shell prompt, run: + +examples/pig$ bin/pig_cassandra -x local + +Once the 'grunt>' shell has loaded, try a simple program like the +following, which will determine the top 50 column names: + - grunt> rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage() AS (key, columns: bag {T: tuple(name, value)}); ++grunt> rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage(); +grunt> cols = FOREACH rows GENERATE flatten(columns); +grunt> colnames = FOREACH cols GENERATE $0; +grunt> namegroups = GROUP colnames BY (chararray) $0; +grunt> namecounts = FOREACH namegroups GENERATE COUNT($1), group; +grunt> orderednames = ORDER namecounts BY $0; +grunt> topnames = LIMIT orderednames 50; +grunt> dump topnames; + +Slices on columns can also be specified: - grunt> rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily&slice_start=C2&slice_end=C4&limit=1&reversed=true' USING CassandraStorage() AS (key, columns: bag {T: tuple(name, value)}); ++grunt> rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily&slice_start=C2&slice_end=C4&limit=1&reversed=true' USING CassandraStorage(); + +Binary values for slice_start and slice_end can be escaped such as '\u0255' + +Outputting to Cassandra requires the same format from input, so the simplest example is: + +grunt> rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage(); +grunt> STORE rows into 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage(); + +Which will copy the ColumnFamily. Note that the destination ColumnFamily must +already exist for this to work. ++ ++See the example in test/ to see how schema is inferred. http://git-wip-us.apache.org/repos/asf/cassandra/blob/3a4459f0/examples/pig/example-script.pig ---------------------------------------------------------------------- diff --cc examples/pig/example-script.pig index f88d773,0000000..74a4602 mode 100644,000000..100644 --- a/examples/pig/example-script.pig +++ b/examples/pig/example-script.pig @@@ -1,8 -1,0 +1,8 @@@ - rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage() AS (key, columns: bag {T: tuple(name, value)}); ++rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage(); +cols = FOREACH rows GENERATE flatten(columns); +colnames = FOREACH cols GENERATE $0; +namegroups = GROUP colnames BY (chararray) $0; +namecounts = FOREACH namegroups GENERATE COUNT($1), group; +orderednames = ORDER namecounts BY $0; +topnames = LIMIT orderednames 50; - dump topnames; ++dump topnames;
