fix: prevent duplicate alias collision with user-provided __datafusion_extracted names (#20432)#81
Draft
Broshen wants to merge 1 commit intoDataDog:mainfrom
Draft
Conversation
…n_extracted names (apache#20432) - Fixes a bug where the optimizer's `AliasGenerator` could produce alias names that collide with`__datafusion_extracted_N` aliases, causing a "Schema contains duplicate unqualified field name" error - I don't expect users themselves to create these aliases, but if you run the optimizers twice (with different `AliasGenerator` instances) you'll hit this. - Adds `AliasGenerator::update_min_id()` to advance the counter past existing aliases - Scans each plan node's expressions during `ExtractLeafExpressions` traversal to seed the generator before any extraction occurs - Switches to controlling the traversal which also means the config-based short circuit more clearly skips the entire rule. Closes apache#20430 - [x] Unit test: `test_user_provided_extracted_alias_no_collision` in `extract_leaf_expressions` - [x] SLT regression test in `projection_pushdown.slt` with explicit `__datafusion_extracted_2` alias 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
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
2 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
AliasGeneratorcould produce alias names that collide with__datafusion_extracted_Naliases, causing a "Schema contains duplicate unqualified field name" errorAliasGeneratorinstances) you'll hit this.AliasGenerator::update_min_id()to advance the counter past existing aliasesExtractLeafExpressionstraversal to seed the generator before any extraction occursCloses apache#20430
test_user_provided_extracted_alias_no_collisioninextract_leaf_expressionsprojection_pushdown.sltwith explicit__datafusion_extracted_2alias🤖 Generated with Claude Code
Which issue does this PR close?
Rationale for this change
What changes are included in this PR?
Are these changes tested?
Are there any user-facing changes?