Hi, Ashotush, Edward, thanks for the comments, answering regarding the deleted UDFs.
1) UDFToDate was a function converting numbers (surprisingly not Writable-s) to java.sql.Date. It was not registered in FunctionRegistry, and not used anyhow else (neither in Java code nor .q scripts). In function registry we have registerUDF("to_date", UDFDate.class, false); (line 271). But its purpose slightly different: it extracts date part from Text or Timestamp writables. Conversion of an arbitrary type to Timestamp is done using org.apache.hadoop.hive.ql.udf.generic.GenericUDFTimestamp.
2) UDFUnixTimeStamp was also not used anyhow, and, as far as I understand, is superseded by the following functions:
These functions are covered well by .q tests.
3) UDFBaseCompare was simply not used. I suppose that all the generic comparison logic was transferred to org.apache.hadoop.hive.ql.udf.generic.GenericUDFBaseCompare and related classes.
If some of these removed classes are still needed, of course, I will change the patch to return them back.