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https://issues.apache.org/jira/browse/HIVE-27186?focusedWorklogId=861113&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-861113
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ASF GitHub Bot logged work on HIVE-27186:
-----------------------------------------

                Author: ASF GitHub Bot
            Created on: 09/May/23 04:06
            Start Date: 09/May/23 04:06
    Worklog Time Spent: 10m 
      Work Description: dengzhhu653 commented on PR #4194:
URL: https://github.com/apache/hive/pull/4194#issuecomment-1539365660

   The latest change overall looks good to me. @saihemanth-cloudera @nrg4878 
Could you please take a look if have a chance? Thanks!




Issue Time Tracking
-------------------

    Worklog Id:     (was: 861113)
    Time Spent: 18h 50m  (was: 18h 40m)

> A persistent property store 
> ----------------------------
>
>                 Key: HIVE-27186
>                 URL: https://issues.apache.org/jira/browse/HIVE-27186
>             Project: Hive
>          Issue Type: Improvement
>          Components: Metastore
>    Affects Versions: 4.0.0-alpha-2
>            Reporter: Henri Biestro
>            Assignee: Henri Biestro
>            Priority: Major
>              Labels: pull-request-available
>          Time Spent: 18h 50m
>  Remaining Estimate: 0h
>
> WHAT
> A persistent property store usable as a support facility for any metadata 
> augmentation feature.
> WHY
> When adding new meta-data oriented features, we usually need to persist 
> information linking the feature data and the HiveMetaStore objects it applies 
> to. Any information related to a database, a table or the cluster - like 
> statistics for example or any operational data state or data (think rolling 
> backup) -  fall in this use-case.
> Typically, accommodating such a feature requires modifying the Metastore 
> database schema by adding or altering a table. It also usually implies 
> modifying the thrift APIs to expose such meta-data to consumers.
> The proposed feature wants to solve the persistence and query/transport for 
> these types of use-cases by exposing a 'key/(meta)value' store exposed as a 
> property system.
> HOW
> A property-value model is the simple and generic exposed API.
> To provision for several usage scenarios, the model entry point is a 
> 'namespace' that qualifies the feature-component property manager. For 
> example, 'stats' could be the namespace for all properties related to the 
> 'statistics' feature.
> The namespace identifies a manager that handles property-groups persisted as 
> property-maps. For instance, all statistics pertaining to a given table would 
> be collocated in the same property-group. As such, all properties (say number 
> of 'unique_values' per columns) for a given HMS table 'relation0' would all 
> be stored and persisted in the same property-map instance.
> Property-maps may be decorated by an (optional) schema that may declare the 
> name and value-type of allowed properties (and their optional default value). 
> Each property is addressed by a name, a path uniquely identifying the 
> property in a given property map.
> The manager also handles transforming property-map names to the property-map 
> keys used to persist them in the DB.
> The API provides inserting/updating properties in bulk transactionally. It 
> also provides selection/projection to help reduce the volume of exchange 
> between client/server; selection can use (JEXL expression) predicates to 
> filter maps.



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