Fix data loading to unblock gvm

Change-Id: I5e145f1e8497d340cb72a8112c247e63b1c79362
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4537
Reviewed-by: Nong Li <nong@cloudera.com>
Reviewed-by: Victor Bittorf <victor.bittorf@cloudera.com>
Tested-by: Victor Bittorf <victor.bittorf@cloudera.com>
Add DECODE builtin

This adds DECODE functionality into the existing CaseExpr class. There
will be no separate backend impementation for DECODE, it will be sent to
the backend as a CASE expr so the existing codegen function can be used.

Because Oracle does cast checking during execution and Impala cast
checking during analysis, some uses of DECODE that are valid in Oracle
are invalid in Impala.

Ex:

  SELECT DECODE(foo, bar, int_col, baz, string_col_containing_only_ints)
  FROM ...

  would be run on Oracle. If string_col_containing_only_ints actually
  contained non-INTs, an error would be thrown during execution and no
  results would be returned. In Impala an error is thrown during analysis.
  If a CAST was added to the STRING column, a cast failure would result in
  NULL.

Change-Id: Ia08cc2389abb6f843bba117e7091c659ad25ff41
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4334
Tested-by: jenkins
Reviewed-by: Casey Ching <casey@cloudera.com>
Tested-by: Casey Ching <casey@cloudera.com>
Implement disabling spilling.

Change-Id: I07951b9c8bcce74a9cb94e1abf9ff36b71e575fc
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4535
Tested-by: jenkins
Reviewed-by: Nong Li <nong@cloudera.com>
IMPALA-1310: Revert parquet file size change temporarily

The parquet writer makes assumptions about having enough space
per column that is not necessarily true for wide tables. Until
I make a real fix for this, revert the parquet file size change
so that the test does not fail.

Change-Id: Ib8199c68fe256ee5e04f81352ab708a8a91c49d9
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4540
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: jenkins