If you are serializing data defined with Avro schemas into HBase then what Rahul said is correct, we should be able to read the columns as they were mapped into HBase with no special setup.
If you are instead saying that you have Avro binary blobs stored in one or more of your HBase columns, then what you are going to need is a UDF to take the binary data and process into the Drill record structure. This is possible because Drill can not only read complex (nested or repeated) data, but it also has full support throughout the engine to manipulate it, so any function can take in or produce a complex data value. The current best example of this is our convert_from function for JSON. This function can take JSON data stored in a varchar value and produce a complex value containing maps and lists. This code [1] is actually really short because it calls into our JSON parser which is shared with the code used to actually read JSON out of files. It does show you how to set up such a function to produce a complex output. Looking at the function that is called here (jsonReader.write(writer)) will show you how the JSON reader can map from the data produced by the Jackson JSON parser into Drill records. You could do something similar with the Avro reader to get access to data stored in a binary column. [1] https://github.com/apache/drill/blob/master/exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/impl/conv/JsonConvertFrom.java On Tue, Sep 29, 2015 at 9:33 AM, rahul challapalli < [email protected]> wrote: > Once you serialized your avro data into hbase, then avro should no longer > come into picture. Now your table is just a normal hbase table. You can > refer to the below documentation on querying hbase tables > > https://drill.apache.org/docs/querying-hbase/ > > - Rahul > > On Tue, Sep 29, 2015 at 12:14 AM, Amandeep Singh <[email protected]> > wrote: > > > Hi, > > > > I need to use sql queries as supported by drill to fetch data from hbase > > which is stored in avro serialized format having predefined schema > > definition. > > Please suggest a way for the same. > > > > Regards, > > Amandeep Singh > > >
