Pushdown subquery when applying distinct in presence of limit #8220
+434
−126
Conversation
This file contains 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
smitpatel
force-pushed
the
distinctissue
branch
from
a1bf0a0 to
57b4cb9
Compare
maumar
approved these changes
Apr 19, 2017
smitpatel
force-pushed
the
distinctissue
branch
from
57b4cb9 to
369fc02
Compare
Distinct clears ordering and in the presence of limit it can create incorrect results. Add counter in RowNumberPagingExpressionVisitor because for a multi level nested subquery, inner subquery can provide column with RowNumber while we are adding it on outer level which causes name clash for a subquery Counter make sure to unique-fy them for given select expression. Moved the visitor to constructor
smitpatel
force-pushed
the
distinctissue
branch
from
369fc02 to
09f3631
Compare
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Outdated suggestions cannot be applied.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.
Distinct clears ordering and in the presence of limit it can create incorrect results.
Add counter in RowNumberPagingExpressionVisitor because for a multi level nested subquery, inner subquery can provide column with RowNumber while we are adding it on outer level which causes name clash for a subquery
Counter make sure to unique-fy them for given select expression.
Moved the visitor to constructor
Resolves #7525