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https://issues.apache.org/jira/browse/ASTERIXDB-2372?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16454783#comment-16454783
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Taewoo Kim edited comment on ASTERIXDB-2372 at 4/26/18 8:11 PM:
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Fact 1. Btree-search is a range search. We need to provide a low value (L) and
a high value (H) and their inclusiveness. For example, a genral B-tree search
query is "id > 1 and id <= 5". In this case, the low value is 1 and the high
value is 5. Also, the low value should not be included in the result and the
high value should be included. For an equality-condition search such as "id =
1" is translated as "id >=1 and id <= 1" to get only one value.
Fact 2. For the equality-condition search, if a float or double value is
provided to an integer index, we transform it to two values - floor( x ) and
ceil( x ). The intuition behind this is that the search only makes sense when
floor( x ) is equal to ceil( x ). This is only true when a float or double
value only contains the integral part (e.g., 1.0, 8.0). For other values, ceil(
x ) is not equal to floor ( x ).
The cause: the cause is that "id = 1.3" will be translated as "id >=1 and id
<=2" because floor(1.3) = 1 and ceil(1.3) = 2. So, two tuples are returned
since AsterixDB removed the SELECT operator that checks "id = 1.3" by providing
that condition to an index-search.
The solution is removing the inclusiveness option when a float value is
translated as two different values when applying ceil() and floor().
Case #1:
query: id = 1.0 (floor(1) = 1 and ceil(1) = 2)
internal: id >=1 and id <= 1 : maintained the inclusiveness
Case #2:
query: id = 1.3 (floor(1.3) = 1 and ceil(1.3) = 2)
internal: id > 1 and id < 2 : removed the inclusiveness
was (Author: wangsaeu):
Fact 1. Btree-search is a range search. We need to provide a low value (L) and
a high value (H) and their inclusiveness. For example, a genral B-tree search
query is "id > 1 and id <= 5". In this case, the low value is 1 and the high
value is 5. Also, the low value should not be included in the result and the
high value should be included. For an equality-condition search such as "id =
1" is translated as "id >=1 and id <= 1" to get only one value.
Fact 2. For the equality-condition search, if a float or double value is
provided to an integer index, we transform it to two values - floor(x) and
ceil(x). The intuition behind this is that the search only makes sense when
floor(x) is equal to ceil(x). This is only true when a float or double value
only contains the integral part (e.g., 1.0, 8.0). For other values, ceil(x) is
not equal to floor(x).
The cause: the cause is that "id = 1.3" will be translated as "id >=1 and id
<=2" because floor(1.3) = 1 and ceil(1.3) = 2. So, two tuples are returned
since AsterixDB removed the SELECT operator that checks "id = 1.3" by providing
that condition to an index-search.
The solution is removing the inclusiveness option when a float value is
translated as two different values when applying ceil() and floor().
Case #1:
query: id = 1.0 (floor(1) = 1 and ceil(1) = 2)
internal: id >=1 and id <= 1 : maintained the inclusiveness
Case #2:
query: id = 1.3 (floor(1.3) = 1 and ceil(1.3) = 2)
internal: id > 1 and id < 2 : removed the inclusiveness
> Providing a float value predicate to an integer primary index does not work
> as expected.
> ----------------------------------------------------------------------------------------
>
> Key: ASTERIXDB-2372
> URL: https://issues.apache.org/jira/browse/ASTERIXDB-2372
> Project: Apache AsterixDB
> Issue Type: Bug
> Reporter: Taewoo Kim
> Assignee: Taewoo Kim
> Priority: Critical
>
> If we have an integer primary index and feed a float value predicate that is
> not an integer such as 1.3, the search result is not correct.
>
> The DDL and DML
> {code:java}
> drop dataverse test if exists;
> create dataverse test;
> use test;
> create type MyRecord as closed {
> id: int64
> };
> create dataset MyData(MyRecord) primary key id;
> insert into MyData({"id":1});
> insert into MyData({"id":2});
> select * from MyData where id = 1.3;{code}
>
> The result should be empty. But, it returns 1 and 2 as the result.
>
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