DRILL-3492: Add support for encoding/decoding of to/from OrderedBytes
format
Description:
This change allows encoding/decoding of data from/to 'double', 'float',
'bigint', 'int' and 'utf8' data types to/from OrderedBytes format.
It also allows for OrderedByte encoded row-keys to be stored in
ascending as well as descending order.
The following JIRA added the OrderedBytes encoding to HBase:
https://issues.apache.org/jira/browse/HBASE-8201
This encoding scheme will preserve the sort-order of the native
data-type when it is stored as sorted byte arrays on disk.
Thus, it will help the HBase storage plugin if the row-keys have been
encoded in OrderedBytes format.
This functionality allows us to prune the scan ranges, thus reading much
lesser data from the server.
Testing Done:
Added a new unit-test class TestOrderedBytesConvertFunctions.java which
derives from TestConvertFunctions.java class.
Also add new test cases to TestHBaseFilterPushDown class that will test
if we were able to push-down filters correctly and if the results are
correct.
DRILL-3492 - * Remove repeated allocations of byte arrays and PositionedByteRange objects
on heap(as suggested by Jason).
* Remove OrderedBytes encode/decode operations on UTF8 types.
Reasons -
1. These operations are slow and incur a lot of heap allocations
2. UTF8 types maintain their natural sort order when stored as binary arrays.
DRILL-3492 - Remove test code that creates test tables with UTF8 OrderedByte encoding.
