[adapters] Delta: report initial frontier in follow&cdc modes. #5457
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Fix the delta connector to report its initial frontier even if it's on the latest table version already. This way the connector will have a non-null frontier even if it never ingests any data. This commit also strengthens existing tests to validate the frontier even after suspend, since we've added support for initializing frontiers after restart some time ago. Signed-off-by: Leonid Ryzhyk <[email protected]>
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Pull request overview
This pull request fixes issue #5447 by ensuring the Delta connector reports its initial frontier even when it's already at the latest table version. This is particularly important for follow and cdc modes where no initial snapshot is read.
Changes:
- Added logic to report initial frontier in follow and CDC modes when no snapshot is being read
- Fixed end_version comparison logic to use
<=instead of==for proper inclusive bound handling - Strengthened existing tests to validate frontier after suspend/resume
- Fixed typo in error message ("has not schema" → "has no schema")
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| crates/adapters/src/integrated/delta_table/input.rs | Added initial frontier reporting for follow/CDC modes (lines 939-948), fixed end_version comparison to properly handle inclusive bounds (lines 970-972), fixed typo in error message (line 1775) |
| crates/adapters/src/integrated/delta_table/test.rs | Added test to verify initial frontier is reported after initial snapshot (lines 890-914), removed conditional around waterline tracking test to enable it for suspend cases (lines 952-969), added new test case for follow mode with suspend (lines 1490-1493) |
abhizer
approved these changes
Jan 18, 2026
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Fixes #5447
Fix the delta connector to report its initial frontier even if it's on the latest table version already. This way the connector will have a non-null frontier even if it never ingests any data.
This commit also strengthens existing tests to validate the frontier even after suspend, since we've added support for initializing frontiers after restart some time ago.