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https://issues.apache.org/jira/browse/DRILL-7421?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Vova Vysotskyi updated DRILL-7421:
----------------------------------
Description:
Drill ignores FILTER clause for aggregate functions.
The following query returns the wrong result:
{code:sql}
select count(*), count(employee_id) filter(where employee_id < 5) from
{code}
{noformat}
cp.`employee.json`;
+--------+--------+
| EXPR$0 | EXPR$1 |
+--------+--------+
| 1155 | 1155 |
+--------+--------+
{noformat}
Calcite already supports this feature (CALCITE-704) and as it is mentioned in
the Jira ticket, such syntax is allowed by SQL standard.
As a short solution, we should throw an exception for such queries that this
functionality is not supported.
As was mentioned in Calcite's Jira, some queries may be rewritten using switch
case:
{code:sql}
select count(*), count(case when employee_id < 5 then employee_id else null
end) from cp.`employee.json`;
{code}
It is possible to add functionality into Drill to rewrite filtered aggregate
calls in such a way, but some aggregate functions still would not be supported,
for example, {{count(\*)}}.
was:
Drill ignores FILTER clause for aggregate functions.
The following query returns the wrong result:
{code:sql}
select count(*), count(employee_id) filter(where employee_id < 5) from
{code}
{noformat}
cp.`employee.json`;
+--------+--------+
| EXPR$0 | EXPR$1 |
+--------+--------+
| 1155 | 1155 |
+--------+--------+
{noformat}
Calcite already supports this feature (CALCITE-704) and as it is mentioned in
the Jira ticket, such syntax is allowed by SQL standard.
As a short solution, we should throw an exception for such queries that this
functionality is not supported.
As was mentioned in Calcite's Jira, some queries may be rewritten using switch
case:
{code:sql}
select count(*), count(case when employee_id < 5 then employee_id else null
end) from cp.`employee.json`;
{code}
It is possible to add functionality into Drill to rewrite filtered aggregate
calls in such a way, but some aggregate functions still would not be supported,
for example, {{count(*)}}.
> FILTER clause for aggregate functions is ignored
> ------------------------------------------------
>
> Key: DRILL-7421
> URL: https://issues.apache.org/jira/browse/DRILL-7421
> Project: Apache Drill
> Issue Type: Bug
> Affects Versions: 1.16.0
> Reporter: Vova Vysotskyi
> Priority: Major
> Fix For: Future
>
>
> Drill ignores FILTER clause for aggregate functions.
> The following query returns the wrong result:
> {code:sql}
> select count(*), count(employee_id) filter(where employee_id < 5) from
> {code}
> {noformat}
> cp.`employee.json`;
> +--------+--------+
> | EXPR$0 | EXPR$1 |
> +--------+--------+
> | 1155 | 1155 |
> +--------+--------+
> {noformat}
> Calcite already supports this feature (CALCITE-704) and as it is mentioned in
> the Jira ticket, such syntax is allowed by SQL standard.
> As a short solution, we should throw an exception for such queries that this
> functionality is not supported.
> As was mentioned in Calcite's Jira, some queries may be rewritten using
> switch case:
> {code:sql}
> select count(*), count(case when employee_id < 5 then employee_id else null
> end) from cp.`employee.json`;
> {code}
> It is possible to add functionality into Drill to rewrite filtered aggregate
> calls in such a way, but some aggregate functions still would not be
> supported, for example, {{count(\*)}}.
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