[
https://issues.apache.org/jira/browse/ORC-1024?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Quanlong Huang reassigned ORC-1024:
-----------------------------------
> BloomFilter hash computation is inconsistent between Java and C++ clients
> -------------------------------------------------------------------------
>
> Key: ORC-1024
> URL: https://issues.apache.org/jira/browse/ORC-1024
> Project: ORC
> Issue Type: Bug
> Components: C++
> Affects Versions: 1.6.11, 1.6.10, 1.6.9, 1.6.8, 1.6.7, 1.7.0, 1.6.6,
> 1.6.5, 1.6.4, 1.6.3, 1.6.2, 1.6.1, 1.6.0
> Reporter: Quanlong Huang
> Assignee: Quanlong Huang
> Priority: Critical
> Attachments: id_name_with_bloom_filters.orc
>
>
> [~drorke] found that the C++ reader could incorrectly filter out some rows
> (RowGroup) when reading Hive generated ORC files with SearchArgument "x =
> value" using some special values. It only happens when Hive generates bloom
> filters in these files.
> I finally reproduced this by using the java tool (with ORC-1023) to generate
> an ORC file with bloom filters, and read it using the c++ reader. Attached
> the orc file (id_name_with_bloom_filters.orc). It contains 2 columns and 3
> rows:
> {code:java}
> {"id": 0, "name": "Alice"}
> {"id": 1, "name": "Bob"}
> {"id": 18000000000, "name": "Mike"}
> {code}
> Using SearchArgument "id = 18000000000" in the C++ reader, no rows will be
> read out.
> Looking into the codes, the Java codes use {{long}} as hash key, while the
> C++ codes use {{uint64_t}} as hash key. {{long}} in Java is signed so should
> correspond to {{int64_t}} in C++. I think this causes the issue.
> In Java codes, the hash key of 18000000000 is -1097054448615658549. In the
> C++ codes, the hash key of it is 15298148493198126027. This results in
> different results in testHash().
> Java codes:
>
> [https://github.com/apache/orc/blob/93b7aa67830104d6bd7fc55399947ee938549f55/java/core/src/java/org/apache/orc/util/BloomFilter.java#L195-L204]
> C++ codes:
>
> [https://github.com/apache/orc/blob/93b7aa67830104d6bd7fc55399947ee938549f55/c%2B%2B/src/BloomFilter.cc#L106-L115]
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
