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https://issues.apache.org/jira/browse/FLINK-5568?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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jingzhang updated FLINK-5568:
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Description:
The {{TableEnvironment}} now provides a mechanism to register temporary table.
It registers the temp table to calcite catalog, so SQL and TableAPI queries can
access to thoese temp tables.
This issue wants to provides an mechanism to connector external catalogs, so
SQL and TableAPI queries could access to tables in the external catalogs
without register those tables to {{TableEnvironment}} beforehand.
First, we should point out that there are two kinds of catalog in Flink
actually.
The first one is external catalog as we mentioned before, it provides CRUD
operations to databases/tables.
The second one is calcite catalog, it defines namespace that can be accessed in
Calcite queries. It depends on Calcite Schema/Table abstraction. SqlValidator
and SqlConverter depends on the calcite catalog to fetch the tables in SQL or
TableAPI.
So we need to do the following things:
1. introduce interface for external catalog, maybe provide an in-memory
implementation first for test and develop environment.
2. introduce a mechanism to connect external catalog with Calcite catalog so
the tables/databases in external catalog can be accessed in Calcite catalog.
Including convert databases of externalCatalog to Calcite sub-schemas, convert
tables in a database of externalCatalog to Calcite tables.
3. register external catalog to {{TableEnvironment}}.
was:
The {TableEnvironment} now provides a mechanism to register temporary table. It
registers the temp table to calcite catalog, so SQL and TableAPI queries can
access to thoese temp tables.
This issue wants to provides an mechanism to connector external catalogs, so
SQL and TableAPI queries could access to tables in the external catalogs
without register those tables to {TableEnvironment} beforehand.
First, we should point out that there are two kinds of catalog in Flink
actually.
The first one is external catalog as we mentioned before, it provides CRUD
operations to databases/tables.
The second one is calcite catalog, it defines namespace that can be accessed in
Calcite queries. It depends on Calcite Schema/Table abstraction. SqlValidator
and SqlConverter depends on the calcite catalog to fetch the tables in SQL or
TableAPI.
So we need to do the following things:
1. introduce interface for external catalog, maybe provide an in-memory
implementation first for test and develop environment.
2. introduce a mechanism to connect external catalog with Calcite catalog so
the tables/databases in external catalog can be accessed in Calcite catalog.
Including convert databases of externalCatalog to Calcite sub-schemas, convert
tables in a database of externalCatalog to Calcite tables.
3. register external catalog to {TableEnvironment}.
> Introduce interface for catalog, and provide an in-memory implementation, and
> integrate with calcite schema
> -----------------------------------------------------------------------------------------------------------
>
> Key: FLINK-5568
> URL: https://issues.apache.org/jira/browse/FLINK-5568
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Reporter: Kurt Young
> Assignee: jingzhang
>
> The {{TableEnvironment}} now provides a mechanism to register temporary
> table. It registers the temp table to calcite catalog, so SQL and TableAPI
> queries can access to thoese temp tables.
> This issue wants to provides an mechanism to connector external catalogs, so
> SQL and TableAPI queries could access to tables in the external catalogs
> without register those tables to {{TableEnvironment}} beforehand.
> First, we should point out that there are two kinds of catalog in Flink
> actually.
> The first one is external catalog as we mentioned before, it provides CRUD
> operations to databases/tables.
> The second one is calcite catalog, it defines namespace that can be accessed
> in Calcite queries. It depends on Calcite Schema/Table abstraction.
> SqlValidator and SqlConverter depends on the calcite catalog to fetch the
> tables in SQL or TableAPI.
> So we need to do the following things:
> 1. introduce interface for external catalog, maybe provide an in-memory
> implementation first for test and develop environment.
> 2. introduce a mechanism to connect external catalog with Calcite catalog so
> the tables/databases in external catalog can be accessed in Calcite catalog.
> Including convert databases of externalCatalog to Calcite sub-schemas,
> convert tables in a database of externalCatalog to Calcite tables.
> 3. register external catalog to {{TableEnvironment}}.
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