chore(dataobj): list pages across all columns in one request #18678
+31
−15
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
Previously, readerDownloader would retrieve page information for projected columns sequentially. This can result in a very high number of roundtrips to object storage: for a streams section with 160 columns, 160 roundtrips at 10ms each would add 1.6s of latency to a scan. This updates readerDownloader to lazily download all page headers at once for all projected columns, once the first page header is requested.
benclive
approved these changes
Jul 31, 2025
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Outdated suggestions cannot be applied.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.
Previously, readerDownloader would retrieve page information for projected columns sequentially. This can result in a very high number of roundtrips to object storage: for a streams section with 160 columns, 160 roundtrips at 10ms each would add 1.6s of latency to a scan.
This updates readerDownloader to lazily download all page headers at once for all projected columns, once the first page header is requested.