[
https://issues.apache.org/jira/browse/FLINK-12841?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16863617#comment-16863617
]
Jark Wu commented on FLINK-12841:
---------------------------------
+1 to the change
> Unify catalog meta-objects implementations and remove their interfaces
> ----------------------------------------------------------------------
>
> Key: FLINK-12841
> URL: https://issues.apache.org/jira/browse/FLINK-12841
> Project: Flink
> Issue Type: Sub-task
> Components: Connectors / Hive, Table SQL / API
> Affects Versions: 1.9.0
> Reporter: Bowen Li
> Assignee: Bowen Li
> Priority: Major
> Fix For: 1.9.0
>
>
> We've been evaluating the original design in FLIP-30 that proposed creating
> catalog meta object interfaces and individual impl of those interfaces in
> each catalog. Interfaces we have so far are: {{CatalogDatabase}},
> {{CatalogTable}}, {{CatalogView}}, {{CatalogPartition}}, {{CatalogFunction}},
> and e.g. for {{CatalogTable}} interface, we have impls of
> {{GenericCatalogTable}} and {{HiveCatalogTable}}, etc.
> Well, we have gone pretty far on FLIP-30 now. When we look back and
> re-evaluate this design, we actually found there are not many differences
> between, e.g. {{GenericCatalogTable}} and {{HiveCatalogTable}}. And having
> this class hierarchy complicates situations and development. E.g. this
> requires sql client to have a hard dependency on flink-connector-hive in
> order to create {{HiveCatalogTable}} from DDL, which I don't think is
> necessary.
> On the other side in Blink, we don't have this hierarchy and have been just
> using a single meta-object class (e.g. just {{CatalogTable}}) to represent
> data in different catalogs, it has been fine without any problem and all the
> difference among catalogs can be stored as properties.
> Thus we propose removing the inheritance hierarchy and impl of the
> meta-object interfaces for each individual catalog. To be more specific, take
> table classes for example, we will replace {{CatalogTable}} with existing
> {{AbstractCatalogTable}}, and remove {{GenericCatalogTable}} and
> {{HiveCatalogTable}}.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
