https://issues.apache.org/jira/browse/DRILL-2012
https://issues.apache.org/jira/browse/DRILL-2013

On Thu, Jan 15, 2015 at 9:51 AM, rahul challapalli <
[email protected]> wrote:

> Hi Ashwin,
>
> Thanks for trying out drill. Below are a few of my comments in blue. For
> the issues found I will raise relevant jira's. Let us know if you have
> further questions.
>
>
> On Thu, Jan 15, 2015 at 8:27 AM, Ashwin Jayaprakash <
> [email protected]> wrote:
>
>> Hello, I was trying to run some queries on a JSON document. I think I may
>> have discovered some bugs. I was using Drill 0.7.0.
>>
>> This is the JSON document (test1.json):
>>
>> {
>>     "id": "0001",
>>     "type": "donut",
>>     "name": "Cake",
>>     "ppu": 0.55,
>>     "batters":
>>         {
>>             "batter":
>>                 [
>>                     { "id": "1001", "type": "Regular" },
>>                     { "id": "1002", "type": "Chocolate" },
>>                     { "id": "1003", "type": "Blueberry" },
>>                     { "id": "1004", "type": "Devil's Food" }
>>                 ]
>>         },
>>     "topping":
>>         [
>>             { "id": "5001", "type": "None" },
>>             { "id": "5002", "type": "Glazed" },
>>             { "id": "5005", "type": "Sugar" },
>>             { "id": "5007", "type": "Powdered Sugar" },
>>             { "id": "5006", "type": "Chocolate with Sprinkles" },
>>             { "id": "5003", "type": "Chocolate" },
>>             { "id": "5004", "type": "Maple" }
>>         ]
>> }
>>
>>
>> 1) I think the parser got confused with the various "type" fields. I think
>> this query is valid as "j.type" is "donut" for the one and only row.
>> Although there are other "type" fields, I believe my query should have
>> worked.
>>
>> select j.id id, j.name name, flatten(j.topping) tt,
>> flatten(j.batters.batter) bb from
>>
>> dfs.root.`/Users/ashwin.jayaprakash/Downloads/apache-drill-0.7.0/sample/test1.json`
>> j where j.type = 'donut';
>> Query failed: Query failed: Failure while running fragment., Trying to
>> flatten a non-repeated filed.
>>
>
> This looks like a bug. You can overcome this by adding the filter column
> to the list of columns in the 'select' part
> *select j.type, j.id <http://j.id> id, j.name <http://j.name> name,
> flatten(j.topping) tt, flatten(j.batters.batter) bb from `sample.json` j
> where j.type = 'donut'; *
>
>>
>>
>> 2) The parser appears to be automatically converting "id" to a tinyint. I
>> suppose this is correct, but wanted your opinion on this.
>>
>> select j.id id, j.name name, flatten(j.topping) tt,
>> flatten(j.batters.batter) bb from
>>
>> dfs.root.`/Users/ashwin.jayaprakash/Downloads/apache-drill-0.7.0/sample/test1.json`
>> j where id = 'donut';
>> Query failed: Query failed: Failure while running fragment., index: -4,
>> length: 4 (expected: range(0, 16384))
>>
>> To my knowledge drill only tries to do an implicit cast based on your
> filter(or join) condition. If you compare a column with a string literal,
> drill tries to cast the column as a string
> The same query works without flatten or by changing your filter condition
> so that the filter condition succeeds. So its most likely a flatten related
> issue
> *select j.id <http://j.id> id, j.name <http://j.name> name from
> `sample.json` j where j.id <http://j.id> = 'donut';*
>
> *select j.id <http://j.id> id, j.name <http://j.name> name,
> flatten(j.topping) tt, flatten(j.batters.batter) bb from `user.json` j
> where j.id <http://j.id> = '0001';*
>
>
>>
>> 3) Isn't there a way to filter the records before the flattening happens
>> by
>> specifying that the path "j.topping.type" should only be "Sugar".
>>
>> select j.id id, j.name name, flatten(j.topping) tt,
>> flatten(j.batters.batter) bb from
>>
>> dfs.root.`/Users/ashwin.jayaprakash/Downloads/apache-drill-0.7.0/sample/test1.json`
>> j where j.topping.type = 'Sugar';
>> Query failed: Query failed: Failure while running fragment.,
>> org.apache.drill.exec.vector.complex.RepeatedMapVector cannot be cast to
>> org.apache.drill.exec.vector.complex.MapVector
>>
>
> You cannot do something like this as of today. However you can apply a
> filter on a particular element in the array.
> *select j.id <http://j.id> id, j.name <http://j.name> name,
> flatten(j.topping) tt, flatten(j.batters.batter) bb from `user.json` j
> where j.topping[2].type = 'Sugar'; *
>
>>
>> 4) Is there a length function supported on the nested arrays?
>>
> I believe not. Some can correct me if I am wrong.
>
>>
>> 5) There is a spelling mistake in the error message :) "Trying to flatten
>> a
>> non-repeated filed." - "filed"
>>
>
> I will raise a JIRA to get this fixed.
>
>>
>> Thanks.
>>
>
>

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