tree 7e86b7933b4a653b4ac0f4e2b054afcb03e89119
parent 5e9f10d34cc2ba6e18b469a3a5ae3ed9f5f306b1
author Adam Tamas <tadam@cloudera.com> 1598622607 +0200
committer Gabor Kaszab <gaborkaszab@cloudera.com> 1599135108 +0000

IMPALA-10133:Implement ds_hll_stringify function.

This function receives a string that is a serialized Apache DataSketches
HLL sketch and returns its stringified format.

A stringified format should look like and contains the following data:

select ds_hll_stringify(ds_hll_sketch(float_col)) from
functional_parquet.alltypestiny;
+--------------------------------------------+
| ds_hll_stringify(ds_hll_sketch(float_col)) |
+--------------------------------------------+
| ### HLL sketch summary:                    |
|   Log Config K   : 12                      |
|   Hll Target     : HLL_4                   |
|   Current Mode   : LIST                    |
|   LB             : 2                       |
|   Estimate       : 2                       |
|   UB             : 2.0001                  |
|   OutOfOrder flag: false                   |
|   Coupon count   : 2                       |
| ### End HLL sketch summary                 |
|                                            |
+--------------------------------------------+

Change-Id: I85dbf20b5114dd75c300eef0accabe90eac240a0
Reviewed-on: http://gerrit.cloudera.org:8080/16382
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>