[jira] [Created] (HIVE-19027) Make materializations invalidation cache work with multiple active remote metastores

["Jesus Camacho Rodriguez (JIRA)" <ji...@apache.org>]

Jesus Camacho Rodriguez created HIVE-19027:
----------------------------------------------

             Summary: Make materializations invalidation cache work with multiple active remote metastores
                 Key: HIVE-19027
                 URL: https://issues.apache.org/jira/browse/HIVE-19027
             Project: Hive
          Issue Type: Improvement
          Components: Materialized views
    Affects Versions: 3.0.0
            Reporter: Jesus Camacho Rodriguez
            Assignee: Jesus Camacho Rodriguez


The main points:
 - Only MVs stored in transactional tables can have a time window value of 0. Those are the only MVs that can be guaranteed to not be outdated when a query is executed, if we use custom storage handlers to store the materialized view, we cannot make any promises.
 - For MVs that +cannot be outdated+, we do not check the metastore. Instead, comparison is based on valid write id lists.
 - For MVs that +can be outdated+, we still rely on the invalidation cache.
 ** The window for valid outdated MVs can be specified in intervals of 1 minute (less than that, it is difficult to have any guarantees about whether the MV is actually outdated by less than a minute or not).
 ** The async loading is done every interval / 2 (or probably better, we can make it configurable).



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)