Jungtaek Lim created SPARK-60691:
------------------------------------
Summary: Add the EXTERNAL_LOOKUP join hint for external lookup join
Key: SPARK-60691
URL: https://issues.apache.org/jira/browse/SPARK-60691
Project: Spark
Issue Type: Task
Components: SQL, Structured Streaming
Affects Versions: 4.4.0
Reporter: Jungtaek Lim
Part of SPARK-60031.
In scope:
- The `EXTERNAL_LOOKUP` hint in DataFrame and SQL forms, bare or naming
relations.
- A dual-capability table (`EXTERNAL_LOOKUP` and `BATCH_READ`) becomes a lookup
join only with the hint; without it, it keeps the ordinary join.
- The lookup side is found through hint markers, aliases, views, projections
and filters, so SQL and catalog table references run.
- A user join hint is never silently overridden:
- a physical strategy hint attaching to a lookup join fails with
`CONFLICTING_JOIN_STRATEGY`;
- a hinted join must also be stream-static (`STATIC_LEFT_SIDE`).
- Error reporting:
- ineligible hinted joins fail with `JOIN_TYPE`, `MISSING_JOIN_CONDITION` or
`STREAMING_LOOKUP_SIDE`;
- misplaced hints fail with `INVALID_EXTERNAL_LOOKUP_HINT` or
`NOT_ON_LOOKUP_SIDE`;
- a hint attached to no join is dropped with a warning.
- USING joins (`df.join(lookup.hint("external_lookup"), "id")`) run.
Out of scope:
- Lookup sides that keep a projection or filter after optimization (they fail
with `LOOKUP_PLAN`).
- Left semi/anti joins, `<=>` and range predicates.
- Hint options, such as cache options.
--
This message was sent by Atlassian Jira
(v10.3.26#10030026)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
