?????? ??Why the NULL will be filterd in HQL??
Thanks for help! ---- ??:"Stamatis
Re: 【Why the NULL will be filterd in HQL】
Hello, I think it would be easier to understand the problem if you have a query at hand: SELECT id FROM author WHERE fname != 'Victor' 0 | Victor 1 | null 2 | Alex The query should return 2 in every standard compliant SQL database. Victor != Victor evaluates to FALSE null != Victor evaluates to UNKNOWN Alex != Victor evaluates to TRUE The WHERE clause removes tuples for which the condition evaluates to FALSE or UNKNOWN and this is the normal behavior. Best, Stamatis On Fri, Jun 26, 2020 at 2:36 AM 忝忝向仧 <153488...@qq.com> wrote: > Hi,all: > > > I want to know why the hive needs to filter the NULL when use '<' or > '!=' in HQL? > Normally,in Oracle or other Databases the NULL will not be filtered when > using '<' or '!='. > This could be a JIRA? > Thanks!
[jira] [Created] (HIVE-23768) Metastore's update service wrongly strips partition column stats from the cache
Stamatis Zampetakis created HIVE-23768: -- Summary: Metastore's update service wrongly strips partition column stats from the cache Key: HIVE-23768 URL: https://issues.apache.org/jira/browse/HIVE-23768 Project: Hive Issue Type: Bug Reporter: Stamatis Zampetakis Assignee: Stamatis Zampetakis Metastore's update service wrongly strips partition column stats from the cache in an attempt to update them. The issue may go unnoticed since missing stats do not lead to query failures. However, they can alter significantly the query plan affecting performance. Moreover, they lead to flakiness since some times the stats are present and sometimes are not leading to a query that has a different plan overtime. Normally missing elements from the cache shouldn't be a correctness problem since we can always fallback to the raw stats. Unfortunately, there are many interconnections with other parts of the code (e.g., code to obtain aggregate statistics) where this contract breaks. -- This message was sent by Atlassian Jira (v8.3.4#803005)
[jira] [Created] (HIVE-23766) Send ValidWriteIDList in request for all the new HMS get_* APIs that are in request/response form
Kishen Das created HIVE-23766: - Summary: Send ValidWriteIDList in request for all the new HMS get_* APIs that are in request/response form Key: HIVE-23766 URL: https://issues.apache.org/jira/browse/HIVE-23766 Project: Hive Issue Type: Task Components: HiveServer2 Reporter: Kishen Das We recently introduced new set of HMS APIs that take ValidWriteIDList in the request, as part of HIVE-22017. We should switch to these new APIs, wherever required and start sending ValidWriteIDList in request for all the new HMS get_* APIs that are in request/response form. -- This message was sent by Atlassian Jira (v8.3.4#803005)
[jira] [Created] (HIVE-23767) Send ValidWriteIDList in request for all the new HMS get_* APIs that are in request/response form
Kishen Das created HIVE-23767: - Summary: Send ValidWriteIDList in request for all the new HMS get_* APIs that are in request/response form Key: HIVE-23767 URL: https://issues.apache.org/jira/browse/HIVE-23767 Project: Hive Issue Type: Sub-task Reporter: Kishen Das We recently introduced new set of HMS APIs that take ValidWriteIDList in the request, as part of HIVE-22017. We should switch to these new APIs, wherever required and start sending ValidWriteIDList in request for all the new HMS get_* APIs that are in request/response form. -- This message was sent by Atlassian Jira (v8.3.4#803005)
