[FLINK-13252] Common CachedLookupFunction for All connector

• Type: New Feature
• Status: Reopened
• Priority: Not a Priority
• Resolution: Unresolved
• Component/s: Connectors / Common, Table SQL / API
• Labels: pull-request-available stale-assigned
• Docs Text: coming soon. lets me know what's your opinions. Thanks.
• Assignee: Chance Li
• Reporter: Chance Li
• Created: 14/Jul/19 16:43
• Updated: 18/Mar/22 15:08

Description

shortly, it's a decorator pattern:

1. A CachedLookupFunction extends TableFunction<Row>
2. when needing the cache feature, the only thing is to construct this CachedLookupFunction with the real LookupFunction's instance.  so it's can be used by any connector.
3. CachedLookupFunction will send the result directly if data has been cached or, to invoke the real LookupFunction to get data and send it after this data has been cached.
4. will have more cache strategies such as All.

should add a new module called flink-connector-common.

we also can provide a common Async LookupFunction using this pattern instead of too much implementation.

Issue Links

• is related to: FLINK-17178 Provide "ALL" cache strategy in LookupFunction
• links to: GitHub Pull Request #9231