expr: fix non-injective text_to_"char"/text_to_bytea uniqueness annotation#36663
Merged
Conversation
…ation These casts were marked `preserves_uniqueness = true`, but neither is injective: `text_to_"char"` keeps only the first byte (so 'a' and 'abc' collapse to the same `"char"`), and `text_to_bytea` accepts both hex and traditional encodings for the same bytes. The annotation made `invert_casts_on_expr_eq_literal_inner` rewrite `col::text = lit` to `col = f_inv(lit)`, which can match rows whose `col::text` does not actually equal `lit` — producing wrong query answers via MFP canonicalization and index literal-constraint lookups. Co-Authored-By: Claude Opus 4.7 (1M context) <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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
These casts were marked
preserves_uniqueness = true, but neither is injective:text_to_"char"keeps only the first byte (so 'a' and 'abc' collapse to the same"char"), andtext_to_byteaaccepts both hex and traditional encodings for the same bytes. The annotation madeinvert_casts_on_expr_eq_literal_innerrewritecol::text = littocol = f_inv(lit), which can match rows whosecol::textdoes not actually equallit— producing wrong query answers via MFP canonicalization and index literal-constraint lookups.