fix: correct typo in README major updates section

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/analyze-metadata-performance.js

@@ -0,0 +1,187 @@
+#!/usr/bin/env node
+
+/**
+ * Metadata Performance Analysis Script
+ * Quick performance analysis of metadata filtering system without full test suite
+ */
+
+import { BrainyData } from '../dist/brainyData.js'
+
+const measureTime = async (fn) => {
+  const start = performance.now()
+  const result = await fn()
+  const end = performance.now()
+  return { result, time: end - start }
+}
+
+const generateTestData = (count) => {
+  const departments = ['Engineering', 'Marketing', 'Sales', 'HR']
+  const levels = ['junior', 'senior', 'staff', 'principal']
+  const locations = ['SF', 'NYC', 'LA', 'Seattle']
+
+  return Array.from({ length: count }, (_, i) => ({
+    text: `Profile ${i}: Professional with experience in software development`,
+    metadata: {
+      id: `profile-${i}`,
+      department: departments[i % departments.length],
+      level: levels[i % levels.length],
+      location: locations[i % locations.length],
+      salary: 50000 + (i % 10) * 10000,
+      remote: i % 3 === 0,
+      active: i % 5 !== 0
+    }
+  }))
+}
+
+async function analyzePerformance() {
+  console.log('=== Metadata Performance Analysis ===\n')
+  
+  // Test 1: Initialization with vs without metadata indexing
+  console.log('1. INITIALIZATION COMPARISON')
+  
+  const testData = generateTestData(100)
+  
+  // Without indexing
+  const withoutIndex = await measureTime(async () => {
+    const brainy = new BrainyData({
+      storage: { forceMemoryStorage: true },
+      logging: { verbose: false }
+    })
+    await brainy.init()
+    
+    for (const item of testData) {
+      await brainy.add(item.text, item.metadata)
+    }
+    
+    return brainy
+  })
+  
+  console.log(`WITHOUT indexing: ${withoutIndex.time.toFixed(2)}ms for 100 items`)
+  
+  // With indexing
+  const withIndex = await measureTime(async () => {
+    const brainy = new BrainyData({
+      storage: { forceMemoryStorage: true },
+      logging: { verbose: false },
+      metadataIndex: { autoOptimize: true }
+    })
+    await brainy.init()
+    
+    for (const item of testData) {
+      await brainy.add(item.text, item.metadata)
+    }
+    
+    return brainy
+  })
+  
+  console.log(`WITH indexing: ${withIndex.time.toFixed(2)}ms for 100 items`)
+  const overhead = ((withIndex.time - withoutIndex.time) / withoutIndex.time) * 100
+  console.log(`Index overhead: ${overhead.toFixed(1)}%\n`)
+  
+  // Test 2: Search Performance Comparison
+  console.log('2. SEARCH PERFORMANCE COMPARISON')
+  
+  const brainy = withIndex.result
+  const searchQuery = 'Professional software development'
+  const numSearches = 5
+  
+  // No filtering
+  let totalNoFilter = 0
+  for (let i = 0; i < numSearches; i++) {
+    const { time } = await measureTime(async () => {
+      return await brainy.search(searchQuery, 10)
+    })
+    totalNoFilter += time
+  }
+  const avgNoFilter = totalNoFilter / numSearches
+  console.log(`No filtering: ${avgNoFilter.toFixed(2)}ms average`)
+  
+  // Simple filtering
+  let totalSimpleFilter = 0
+  for (let i = 0; i < numSearches; i++) {
+    const { time } = await measureTime(async () => {
+      return await brainy.search(searchQuery, 10, {
+        metadata: { department: 'Engineering' }
+      })
+    })
+    totalSimpleFilter += time
+  }
+  const avgSimpleFilter = totalSimpleFilter / numSearches
+  console.log(`Simple filter: ${avgSimpleFilter.toFixed(2)}ms average`)
+  
+  // Complex filtering
+  let totalComplexFilter = 0
+  for (let i = 0; i < numSearches; i++) {
+    const { time } = await measureTime(async () => {
+      return await brainy.search(searchQuery, 10, {
+        metadata: {
+          department: { $in: ['Engineering', 'Marketing'] },
+          level: { $in: ['senior', 'staff'] },
+          salary: { $gte: 80000 }
+        }
+      })
+    })
+    totalComplexFilter += time
+  }
+  const avgComplexFilter = totalComplexFilter / numSearches
+  console.log(`Complex filter: ${avgComplexFilter.toFixed(2)}ms average`)
+  
+  console.log('\nSearch Performance Impact:')
+  console.log(`Simple filter overhead: ${((avgSimpleFilter / avgNoFilter - 1) * 100).toFixed(1)}%`)
+  console.log(`Complex filter overhead: ${((avgComplexFilter / avgNoFilter - 1) * 100).toFixed(1)}%\n`)
+  
+  // Test 3: Index Statistics
+  console.log('3. INDEX STATISTICS')
+  
+  if (brainy.metadataIndex) {
+    const stats = await brainy.metadataIndex.getStats()
+    console.log(`Total index entries: ${stats.totalEntries}`)
+    console.log(`Total indexed IDs: ${stats.totalIds}`)
+    console.log(`Fields indexed: ${stats.fieldsIndexed.join(', ')}`)
+    console.log(`Estimated index size: ${stats.indexSize} bytes`)
+    console.log(`Storage overhead per item: ${(stats.indexSize / 100).toFixed(2)} bytes\n`)
+  }
+  
+  // Test 4: Write Performance
+  console.log('4. WRITE PERFORMANCE ANALYSIS')
+  
+  const newTestData = generateTestData(50)
+  
+  // Add performance
+  const { time: addTime } = await measureTime(async () => {
+    for (const item of newTestData) {
+      await brainy.add(item.text, item.metadata)
+    }
+  })
+  console.log(`ADD: 50 items in ${addTime.toFixed(2)}ms (${(addTime / 50).toFixed(2)}ms per item)`)
+  
+  // Update performance
+  const updateData = newTestData.slice(0, 20).map(item => ({
+    ...item,
+    metadata: { ...item.metadata, level: 'updated', salary: item.metadata.salary + 10000 }
+  }))
+  
+  const { time: updateTime } = await measureTime(async () => {
+    for (const item of updateData) {
+      await brainy.updateMetadata(item.metadata.id, item.metadata)
+    }
+  })
+  console.log(`UPDATE: 20 items in ${updateTime.toFixed(2)}ms (${(updateTime / 20).toFixed(2)}ms per item)`)
+  
+  // Delete performance
+  const idsToDelete = newTestData.slice(30, 40).map(item => item.metadata.id)
+  const { time: deleteTime } = await measureTime(async () => {
+    for (const id of idsToDelete) {
+      await brainy.delete(id)
+    }
+  })
+  console.log(`DELETE: 10 items in ${deleteTime.toFixed(2)}ms (${(deleteTime / 10).toFixed(2)}ms per item)\n`)
+  
+  // Cleanup
+  await withoutIndex.result.shutDown()
+  await withIndex.result.shutDown()
+  
+  console.log('Analysis complete!')
+}
+
+analyzePerformance().catch(console.error)