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https://issues.apache.org/jira/browse/DRILL-6094?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16435914#comment-16435914
]
Vitalii Diravka edited comment on DRILL-6094 at 4/13/18 6:16 AM:
-----------------------------------------------------------------
Looks like ARROW-61 is not an issue for Drill anymore.
Drill 1.6.0 version:
{code:java}
SELECT CAST('922337203685477587' as DECIMAL(18, 0)) > CAST('0.1' as DECIMAL(18,
1)) IS_FIRST_GREATER FROM (VALUES(1))
--------------------------------------
| IS_FIRST_GREATER<BIT(REQUIRED)> |
--------------------------------------
| false |
--------------------------------------
select _DECIMAL_decimal18 > _DECIMAL_decimal18_2 IS_FIRST_GREATER,
_DECIMAL_decimal18, _DECIMAL_decimal18_2 from
dfs.`/tmp/parquet/drill/parquet_test_file_simple` t
----------------------------------------------------------------------------------------------------------------
| IS_FIRST_GREATER<BIT(REQUIRED)> | _DECIMAL_decimal18<DECIMAL18(REQUI |
_DECIMAL_decimal18_2<DECIMAL18(REQ |
----------------------------------------------------------------------------------------------------------------
| false | 922337203685477587 | 0.1
|
----------------------------------------------------------------------------------------------------------------
{code}
Current Drill master:
{code:java}
SELECT CAST('922337203685477587' as DECIMAL(18, 0)) > CAST('0.1' as DECIMAL(18,
1)) IS_FIRST_GREATER FROM (VALUES(1))
----------------------------------------------------------------------------------------------------------------
IS_FIRST_GREATER<BIT(REQUIRED)>
true
select _DECIMAL_decimal18 > _DECIMAL_decimal18_2 IS_FIRST_GREATER,
_DECIMAL_decimal18, _DECIMAL_decimal18_2" +
" from dfs.root.`/tmp/parquet/drill/parquet_test_file_simple` t
----------------------------------------------------------------------------------------------------------------
IS_FIRST_GREATER<BIT(REQUIRED)>,_DECIMAL_decimal18<DECIMAL18(REQUIRED)>,_DECIMAL_decimal18_2<DECIMAL18(REQUIRED)>
true,922337203685477587,0.1
{code}
For the first query Calcite simplifies the predicaste in the project to true
and for the second query casting to FLOAT8 is used now (and FLOAT8 values are
compared).
Therefore _adjustScaleMultiply_ is still buggy and isn't needed anymore (after
moving to VARDECIMAL) I would recommend to remove it from the project or to
make it deprecated.
was (Author: vitalii):
Looks like ARROW-61 is not an issue for Drill anymore.
Drill 1.6.0 version:
{code:java}
SELECT CAST('922337203685477587' as DECIMAL(18, 0)) > CAST('0.1' as DECIMAL(18,
1)) IS_FIRST_GREATER FROM (VALUES(1))
--------------------------------------
| IS_FIRST_GREATER<BIT(REQUIRED)> |
--------------------------------------
| false |
--------------------------------------
select _DECIMAL_decimal18 > _DECIMAL_decimal18_2 IS_FIRST_GREATER,
_DECIMAL_decimal18, _DECIMAL_decimal18_2 from
dfs.`/tmp/parquet/drill/parquet_test_file_simple` t
----------------------------------------------------------------------------------------------------------------
| IS_FIRST_GREATER<BIT(REQUIRED)> | _DECIMAL_decimal18<DECIMAL18(REQUI |
_DECIMAL_decimal18_2<DECIMAL18(REQ |
----------------------------------------------------------------------------------------------------------------
| false | 922337203685477587 | 0.1
|
----------------------------------------------------------------------------------------------------------------
{code}
Current Drill master:
{code:java}
SELECT CAST('922337203685477587' as DECIMAL(18, 0)) > CAST('0.1' as DECIMAL(18,
1)) IS_FIRST_GREATER FROM (VALUES(1))
----------------------------------------------------------------------------------------------------------------
IS_FIRST_GREATER<BIT(REQUIRED)>
true
select _DECIMAL_decimal18 > _DECIMAL_decimal18_2 IS_FIRST_GREATER,
_DECIMAL_decimal18, _DECIMAL_decimal18_2" +
" from dfs.root.`/tmp/parquet/drill/parquet_test_file_simple` t
----------------------------------------------------------------------------------------------------------------
IS_FIRST_GREATER<BIT(REQUIRED)>,_DECIMAL_decimal18<DECIMAL18(REQUIRED)>,_DECIMAL_decimal18_2<DECIMAL18(REQUIRED)>
true,922337203685477587,0.1
{code}
For the first query Calcite simplifies the predicaste in the project to true
and for the second query casting to FLOAT8 is used now (and FLOAT8 values are
compared).
Therefore _adjustScaleMultiply_ is still buggy and isn't needed anymore (after
moving to VARDECIMAL) I would recommend to remove it from the project.
> Decimal data type enhancements
> ------------------------------
>
> Key: DRILL-6094
> URL: https://issues.apache.org/jira/browse/DRILL-6094
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.12.0
> Reporter: Volodymyr Vysotskyi
> Assignee: Volodymyr Vysotskyi
> Priority: Major
>
> Currently, Decimal types are disabled by default since existing Decimal
> implementation has a lot of flaws and performance problems. The goal of this
> Jira to describe majority of them and possible ways of improving existing
> implementation to be able to enable Decimal data types by default.
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