fix: default MVStore pageSplitSize to 16 KB, not 16 bytes - #1293
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anidotnet merged 1 commit intoSep 4, 2026
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MVStoreModuleBuilder.pageSplitSize is documented as "16 KB" and is passed straight to MVStore.Builder.pageSplitSize, which takes bytes. Its value was 16, the same literal used for cacheSize (megabytes) and cacheConcurrency (a count), so every leaf page split as soon as it held more than one entry. Measured by rebuilding a 146 MB store of 46,926 entries at each setting: 93,781 pages at depth 13 with 16; 36,096 pages at depth 12 with MVStore's own persistent-store default of 16 KB; 13,327 pages at depth 6 with 64 KB, the largest value that survives H2's (cacheSize / cacheConcurrency) >> 4 clamp. The default is now 16 * 1024, matching the javadoc and MVStore's default. Existing files are unaffected until their pages are rewritten; there is nothing to migrate. The two tests that pinned the old literal through Short.SIZE are updated. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Included review availability: Your plan provides up to 4 included reviews per hour; 2 remain after this review. 📝 WalkthroughWalkthroughThe MVStore module default page split size changed from 16 bytes to 16 KB. Documentation and constructor and configuration tests now use the updated default. ChangesMVStore page split default
Estimated code review effort: 2 (Simple) | ~10 minutes Merge Risk: ⚪ Minimal · up to This corrects the default MVStore page split size to 16 KB and aligns its tests and documentation. No current merge-blocking risk is identified. 🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
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This was referenced Sep 4, 2026
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MVStoreModuleBuilder.pageSplitSize is documented as "16 KB" and is passed straight to MVStore.Builder.pageSplitSize, which takes bytes. Its value was 16, the same literal used for cacheSize (megabytes) and cacheConcurrency (a count), so every leaf page split as soon as it held more than one entry.
Measured by rebuilding a 146 MB store of 46,926 entries at each setting: 93,781 pages at depth 13 with 16; 36,096 pages at depth 12 with MVStore's own persistent-store default of 16 KB; 13,327 pages at depth 6 with 64 KB, the largest value that survives H2's (cacheSize / cacheConcurrency) >> 4 clamp.
The default is now 16 * 1024, matching the javadoc and MVStore's default. Existing files are unaffected until their pages are rewritten; there is nothing to migrate. The two tests that pinned the old literal through Short.SIZE are updated.
Summary by CodeRabbit
Bug Fixes
Documentation