feat(mem_wal): tombstone-preserving point lookup#7482
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jackye1995 merged 1 commit intoJun 26, 2026
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Add `LsmPointLookupPlanner::lookup_keep_tombstone` and `lookup_many_keep_tombstone`: point-lookup variants that carry the `_tombstone` marker through instead of filtering deleted keys out. The existing `lookup` collapses "deleted in the fresh tier" and "absent" into a single `None`; these variants distinguish them by returning the deleted row with `_tombstone = true` (absent keys still return `None`). Refactors `plan_lookup` to share `plan_lookup_coalesced`, leaving the hot read path unchanged. The sophon WAL partial-column-update merge uses this to treat a fresh-deleted PK as absent rather than resurrecting stale base columns. Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
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## What Adds `LsmPointLookupPlanner::lookup_keep_tombstone` and `lookup_many_keep_tombstone` — point-lookup variants that carry the `_tombstone` marker through instead of filtering deleted keys out. ## Why The existing `lookup` / `lookup_many` collapse two distinct states — **deleted in the fresh tier** and **never written** — into a single `None`. That's correct for a normal reader, but a caller doing a read-on-write merge needs to tell them apart: a fresh-deleted PK must be treated as *absent* (so a later partial update resurrects it from carried columns + NULLs), while a never-written PK falls back to the base row. These variants return the deleted row with `_tombstone = true`; absent keys still return `None`. Implemented by refactoring `plan_lookup` to share a `plan_lookup_coalesced` helper and skipping the post-coalesce tombstone filter, so the hot read path is unchanged. ## Tests - `test_lookup_keep_tombstone_returns_deleted_row_with_marker` - `test_lookup_many_keep_tombstone_includes_tombstoned_keys` ## Context Prerequisite for a downstream WAL partial-column-update resurrection fix: a partial update arriving after a delete must resurrect carried columns + NULL untouched, never stale pre-delete base data. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>
BubbleCal
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Backport of the following PRs: - #7362 - #7417 - #7482 - #7483 - #7489 This PR backports the changes from the original PRs to the release/v8.0 branch. --------- Co-authored-by: Dan Rammer <[email protected]> Co-authored-by: Lance Release Bot <[email protected]> Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>
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What
Adds
LsmPointLookupPlanner::lookup_keep_tombstoneandlookup_many_keep_tombstone— point-lookup variants that carry the_tombstonemarker through instead of filtering deleted keys out.Why
The existing
lookup/lookup_manycollapse two distinct states — deleted in the fresh tier and never written — into a singleNone. That's correct for a normal reader, but a caller doing a read-on-write merge needs to tell them apart: a fresh-deleted PK must be treated as absent (so a later partial update resurrects it from carried columns + NULLs), while a never-written PK falls back to the base row.These variants return the deleted row with
_tombstone = true; absent keys still returnNone. Implemented by refactoringplan_lookupto share aplan_lookup_coalescedhelper and skipping the post-coalesce tombstone filter, so the hot read path is unchanged.Tests
test_lookup_keep_tombstone_returns_deleted_row_with_markertest_lookup_many_keep_tombstone_includes_tombstoned_keysContext
Prerequisite for a downstream WAL partial-column-update resurrection fix: a partial update arriving after a delete must resurrect carried columns + NULL untouched, never stale pre-delete base data.
🤖 Generated with Claude Code