The post-import background deduplication pass (a merge-DELETE writer,
debounced ~5 minutes after import) had four lifecycle defects:
- enableDeduplication: false did not gate the background schedule — an
import that explicitly opted out could still have entities auto-removed
minutes later. The flag now gates both the inline and background passes.
- Each import() constructed its own coordinator-owned deduplicator, so the
debounce never spanned imports (N imports = N delete timers). The brain
now owns a single lazy instance (getBackgroundDeduplicator).
- close() never cancelled pending dedup; a delete pass could fire against
a closed brain. close() now cancels it first.
- The 5-minute timer held the process open (exit-hang class); now unref'd.
Four regression tests pin the contract (background-dedup-lifecycle);
import guides document that false disables both passes.
The __words__ keyword index stores 50-5000 entries per entity (one per
word), which inflated avg entries/entity well above the corruption
threshold of 100. This caused:
1. validateConsistency() to falsely detect corruption on every startup,
triggering unnecessary clearAllIndexData() + rebuild() cycles
2. getStats() to log false "Metadata index may be corrupted" warnings
and report inflated totalEntries/totalIds stats
Both methods now skip __words__ when counting, so stats and health
checks reflect metadata fields only (noun, type, createdAt, etc.).
Keyword search is unaffected since the __words__ field index itself
is not modified.
Progressive intervals adjust dynamically based on current entity count
(not total), making them work for both known and unknown totals.
**Key Features:**
- 0-999 entities: Flush every 100 (frequent early updates for UX)
- 1K-9.9K: Flush every 1000 (balanced performance)
- 10K+: Flush every 5000 (minimal overhead ~0.3%)
**Benefits:**
- Works with known totals (file imports)
- Works with unknown totals (streaming APIs, database cursors)
- Adapts automatically as import grows
- Zero configuration required
**Implementation:**
- Replaced adaptive intervals (requires total count) with progressive
- Added interval transition logging for observability
- Enhanced documentation to highlight engineering sophistication
- Final flush with statistics reporting
**Documentation:**
- Added "Engineering Insight" section showcasing advanced approach
- Updated all interval references from "adaptive" to "progressive"
- Added comprehensive examples in streaming-imports.md
Generated with Claude Code (https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
