Semi join and FDs bug #2006
Merged
Semi join and FDs bug #2006
Conversation
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
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Outdated suggestions cannot be applied.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.
Returning no projections from a table causes "column not found errors" when we try to reference those expressions higher in the tree. This fixes the semi join transform to creating empty projections.
This fixes two bugs. The first is that we were too conservative checking whether index keys were strict FDs for a join relation. When a relation has a constant applied to a primary key, we can assume all of the columns returned by that join will be constant. Fixing that made it easer to test certain semi -> right lookup join transforms which were buggy. For the same case, when we are doing a lookup into table where a constant filter satisfies an index key, we need to still return a projection set that covers non-pruneable columns used in higher-level nodes.