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ASF GitHub Bot logged work on HIVE-27186: ----------------------------------------- Author: ASF GitHub Bot Created on: 03/Apr/23 17:11 Start Date: 03/Apr/23 17:11 Worklog Time Spent: 10m Work Description: henrib opened a new pull request, #4194: URL: https://github.com/apache/hive/pull/4194 [https://issues.apache.org/jira/browse/HIVE-27186](https://issues.apache.org/jira/browse/HIVE-27186) A persistent property store usable as a support facility for any metadata augmentation feature. ### What changes were proposed in this pull request? 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. ### Why are the changes needed? 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. ### Does this PR introduce _any_ user-facing change? It introduces new API calls. ### How was this patch tested? Junit + coverage Issue Time Tracking ------------------- Worklog Id: (was: 854591) Remaining Estimate: 0h Time Spent: 10m > 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 > Priority: Major > Time Spent: 10m > 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. -- This message was sent by Atlassian Jira (v8.20.10#820010)