Add UNION ALL to the unified query SQL path#5506
Merged
dai-chen merged 1 commit intoJun 3, 2026
Merged
Conversation
Add UNION and UNION ALL set operations to the Calcite-based unified query path. Extend the SQL grammar with a unionSelect rule, add a distinct-aware Union AST node and DSL factory, and translate to a Calcite LogicalUnion (all=true for UNION ALL, all=false for UNION). The legacy V2 SQL engine rejects UNION with a SyntaxCheckException so queries fall back to the legacy engine appropriately. Signed-off-by: Chen Dai <daichen@amazon.com>
dai-chen
requested review from
LantaoJin,
RyanL1997,
Swiddis,
acarbonetto,
ahkcs,
anirudha,
joshuali925,
mengweieric,
noCharger,
penghuo,
ps48,
qianheng-aws,
songkant-aws,
vamsimanohar,
ykmr1224 and
yuancu
as code owners
ahkcs
approved these changes
Jun 3, 2026
mengweieric
approved these changes
Jun 3, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Description
Adds SQL
UNION ALLsupport to the unified query path; the legacy V2 engine continues to rejectUNIONand fall back.UNION (DISTINCT)andMINUSare deferred because the Analytics Engine currently supports onlyUNION ALL(PPL-only).ORDER BY/LIMITbinds to the last SELECT branch instead of the entire unioned result; fixing it would require major changes to thequerySpecificationgrammar that could impact all V2 SQL queries.Related Issues
Part of #5248.
Check List
--signoffor-s.By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.