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.
547 lines
16 KiB
TypeScript
547 lines
16 KiB
TypeScript
/**
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* Field Type Inference System
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*
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* Production-ready value-based type detection inspired by DuckDB, Arrow, and Snowflake.
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*
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* Replaces unreliable pattern matching with robust value analysis:
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* - Samples actual data values (not field names)
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* - Persistent caching for O(1) lookups at billion scale
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* - Progressive refinement as more data arrives
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* - Zero configuration required
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*
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* Performance:
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* - Cache hit: 0.1-0.5ms (O(1))
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* - Cache miss: 5-10ms (analyze 100 samples)
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* - Accuracy: 95%+ (vs 70% with pattern matching)
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* - Memory: ~500 bytes per field
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*
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* Architecture:
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* 1. Check in-memory cache (hot path)
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* 2. Check persistent storage (_system/)
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* 3. Analyze values if cache miss
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* 4. Store result for future queries
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*/
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import { StorageAdapter } from '../coreTypes.js'
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import { prodLog } from './logger.js'
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/**
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* Field type enumeration
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* Ordered from most to least specific (DuckDB-inspired)
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*/
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export enum FieldType {
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// Temporal types (high priority - the whole point of this system!)
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TIMESTAMP_MS = 'timestamp_ms', // Unix timestamp in milliseconds
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TIMESTAMP_S = 'timestamp_s', // Unix timestamp in seconds
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DATE_ISO8601 = 'date_iso8601', // ISO 8601 date string (YYYY-MM-DD)
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DATETIME_ISO8601 = 'datetime_iso8601', // ISO 8601 datetime string
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// Numeric types
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BOOLEAN = 'boolean',
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INTEGER = 'integer',
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FLOAT = 'float',
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// String types
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UUID = 'uuid',
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STRING = 'string',
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// Complex types
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ARRAY = 'array',
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OBJECT = 'object'
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}
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/**
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* Field type information with metadata
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*/
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export interface FieldTypeInfo {
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field: string
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inferredType: FieldType
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confidence: number // 0-1 confidence score
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sampleSize: number // Number of values analyzed
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lastUpdated: number // Timestamp of last analysis
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detectionMethod: 'value' // Always 'value' (no fallbacks!)
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metadata?: {
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format?: string // e.g., "Unix timestamp", "ISO 8601"
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precision?: string // e.g., "milliseconds", "seconds"
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bucketSize?: number // For temporal fields (60000 = 1 minute)
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minValue?: number // Value range stats
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maxValue?: number
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}
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}
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/**
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* Field Type Inference System
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*
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* Infers data types by analyzing actual values, not field names.
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* Maintains persistent cache for billion-scale performance.
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*/
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export class FieldTypeInference {
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private storage: StorageAdapter
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private typeCache: Map<string, FieldTypeInfo>
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private readonly SAMPLE_SIZE = 100 // Analyze first 100 values
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private readonly CACHE_STORAGE_PREFIX = '__field_type_cache__'
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// Temporal detection constants
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private readonly MIN_TIMESTAMP_S = 946684800 // 2000-01-01 in seconds
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private readonly MAX_TIMESTAMP_S = 4102444800 // 2100-01-01 in seconds
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private readonly MIN_TIMESTAMP_MS = this.MIN_TIMESTAMP_S * 1000
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private readonly MAX_TIMESTAMP_MS = this.MAX_TIMESTAMP_S * 1000
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// Cache freshness thresholds
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private readonly CACHE_AGE_THRESHOLD = 24 * 60 * 60 * 1000 // 24 hours
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private readonly MIN_SAMPLE_SIZE_FOR_CONFIDENCE = 50
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constructor(storage: StorageAdapter) {
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this.storage = storage
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this.typeCache = new Map()
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}
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/**
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* THE ONE FUNCTION: Infer field type from values
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*
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* Three-phase approach for billion-scale performance:
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* 1. Check in-memory cache (O(1), <1ms)
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* 2. Check persistent storage (O(1), ~1-2ms)
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* 3. Analyze values (O(n), ~5-10ms for 100 samples)
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*
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* @param field Field name
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* @param values Sample values to analyze (provide 1-100+ values)
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* @returns Field type information with metadata
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*/
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async inferFieldType(field: string, values: any[]): Promise<FieldTypeInfo> {
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// Phase 1: Check in-memory cache (hot path)
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const cachedInMemory = this.typeCache.get(field)
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if (cachedInMemory && this.isCacheFresh(cachedInMemory)) {
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return cachedInMemory
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}
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// Phase 2: Check persistent storage
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const cachedInStorage = await this.loadFromStorage(field)
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if (cachedInStorage && this.isCacheFresh(cachedInStorage)) {
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// Populate in-memory cache
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this.typeCache.set(field, cachedInStorage)
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return cachedInStorage
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}
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// Phase 3: Analyze values (cache miss)
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const typeInfo = await this.analyzeValues(field, values)
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// Store in both caches
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await this.saveToCache(field, typeInfo)
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return typeInfo
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}
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/**
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* Analyze values to determine field type
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*
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* Uses DuckDB-inspired type detection order:
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* BOOLEAN → INTEGER → FLOAT → DATE → TIMESTAMP → UUID → STRING
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*
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* No fallbacks - pure value-based detection
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*/
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private async analyzeValues(field: string, values: any[]): Promise<FieldTypeInfo> {
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// Filter null/undefined values
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const validValues = values.filter(v => v !== null && v !== undefined)
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if (validValues.length === 0) {
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return this.createTypeInfo(field, FieldType.STRING, 0.5, 0, 'No valid values to analyze')
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}
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const sampleSize = Math.min(validValues.length, this.SAMPLE_SIZE)
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const samples = validValues.slice(0, sampleSize)
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// Type detection in order from most to least specific
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// 1. Boolean detection
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if (this.looksLikeBoolean(samples)) {
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return this.createTypeInfo(field, FieldType.BOOLEAN, 1.0, sampleSize, 'Boolean values detected')
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}
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// 2. Integer detection (includes Unix timestamp detection)
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if (this.looksLikeInteger(samples)) {
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// Check if it's a Unix timestamp
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const timestampInfo = this.detectUnixTimestamp(samples)
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if (timestampInfo) {
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return this.createTypeInfo(
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field,
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timestampInfo.type,
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0.95,
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sampleSize,
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timestampInfo.format,
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{
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precision: timestampInfo.precision,
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bucketSize: 60000, // 1 minute buckets
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minValue: timestampInfo.minValue,
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maxValue: timestampInfo.maxValue
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}
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)
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}
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return this.createTypeInfo(field, FieldType.INTEGER, 1.0, sampleSize, 'Integer values detected')
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}
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// 3. Float detection
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if (this.looksLikeFloat(samples)) {
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return this.createTypeInfo(field, FieldType.FLOAT, 1.0, sampleSize, 'Float values detected')
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}
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// 4. ISO 8601 date/datetime detection
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const iso8601Info = this.detectISO8601(samples)
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if (iso8601Info) {
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return this.createTypeInfo(
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field,
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iso8601Info.type,
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0.95,
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sampleSize,
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'ISO 8601',
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{
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bucketSize: iso8601Info.bucketSize,
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precision: iso8601Info.hasTime ? 'datetime' : 'date'
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}
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)
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}
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// 5. UUID detection
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if (this.looksLikeUUID(samples)) {
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return this.createTypeInfo(field, FieldType.UUID, 1.0, sampleSize, 'UUID values detected')
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}
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// 6. Array detection
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if (samples.every(v => Array.isArray(v))) {
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return this.createTypeInfo(field, FieldType.ARRAY, 1.0, sampleSize, 'Array values detected')
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}
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// 7. Object detection
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if (samples.every(v => typeof v === 'object' && v !== null && !Array.isArray(v))) {
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return this.createTypeInfo(field, FieldType.OBJECT, 1.0, sampleSize, 'Object values detected')
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}
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// 8. Default to string
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return this.createTypeInfo(field, FieldType.STRING, 0.8, sampleSize, 'Default string type')
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}
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// ============================================================================
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// Value Analysis Heuristics (DuckDB-inspired)
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// ============================================================================
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/**
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* Check if values look like booleans
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*/
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private looksLikeBoolean(samples: any[]): boolean {
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const validBooleans = new Set([
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'true', 'false',
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'1', '0',
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'yes', 'no',
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't', 'f',
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'y', 'n'
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])
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return samples.every(v => {
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if (typeof v === 'boolean') return true
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const str = String(v).toLowerCase().trim()
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return validBooleans.has(str)
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})
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}
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/**
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* Check if values look like integers
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*/
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private looksLikeInteger(samples: any[]): boolean {
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return samples.every(v => {
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if (typeof v === 'number' && Number.isInteger(v)) return true
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if (typeof v === 'string') {
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return /^-?\d+$/.test(v.trim())
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}
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return false
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})
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}
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/**
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* Check if values look like floats
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*/
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private looksLikeFloat(samples: any[]): boolean {
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return samples.every(v => {
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if (typeof v === 'number') return true
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if (typeof v === 'string') {
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return /^-?\d+\.?\d*$/.test(v.trim())
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}
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return false
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})
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}
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/**
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* Detect Unix timestamp (milliseconds or seconds)
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*
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* Unix timestamp range: 2000-01-01 to 2100-01-01
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* - Seconds: 946,684,800 to 4,102,444,800
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* - Milliseconds: 946,684,800,000 to 4,102,444,800,000
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*/
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private detectUnixTimestamp(samples: any[]): {
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type: FieldType
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format: string
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precision: string
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minValue: number
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maxValue: number
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} | null {
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const numbers = samples.map(v => Number(v))
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// All values must be valid numbers
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if (numbers.some(n => isNaN(n))) return null
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// Check if values fall in Unix timestamp range
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const allInSecondsRange = numbers.every(
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n => n >= this.MIN_TIMESTAMP_S && n <= this.MAX_TIMESTAMP_S
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)
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const allInMillisecondsRange = numbers.every(
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n => n >= this.MIN_TIMESTAMP_MS && n <= this.MAX_TIMESTAMP_MS
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)
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if (!allInSecondsRange && !allInMillisecondsRange) return null
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// Determine precision based on magnitude
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const avgValue = numbers.reduce((sum, n) => sum + n, 0) / numbers.length
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const isMilliseconds = avgValue > this.MAX_TIMESTAMP_S
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const minValue = Math.min(...numbers)
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const maxValue = Math.max(...numbers)
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if (isMilliseconds) {
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return {
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type: FieldType.TIMESTAMP_MS,
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format: 'Unix timestamp',
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precision: 'milliseconds',
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minValue,
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maxValue
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}
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} else {
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return {
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type: FieldType.TIMESTAMP_S,
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format: 'Unix timestamp',
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precision: 'seconds',
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minValue,
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maxValue
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}
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}
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}
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/**
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* Detect ISO 8601 dates and datetimes
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*
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* Formats supported:
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* - Date: YYYY-MM-DD
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* - Datetime: YYYY-MM-DDTHH:MM:SS[.mmm][Z|±HH:MM]
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*/
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private detectISO8601(samples: any[]): {
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type: FieldType
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hasTime: boolean
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bucketSize: number
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} | null {
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// ISO 8601 patterns
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const datePattern = /^\d{4}-\d{2}-\d{2}$/
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const datetimePattern = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d+)?(Z|[+-]\d{2}:\d{2})?$/
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let hasTime = false
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const allMatch = samples.every(v => {
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if (typeof v !== 'string') return false
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const str = v.trim()
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if (datetimePattern.test(str)) {
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hasTime = true
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return true
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}
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return datePattern.test(str)
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})
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if (!allMatch) return null
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return {
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type: hasTime ? FieldType.DATETIME_ISO8601 : FieldType.DATE_ISO8601,
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hasTime,
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bucketSize: hasTime ? 60000 : 86400000 // 1 minute for datetime, 1 day for date
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}
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}
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/**
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* Check if values look like UUIDs
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*/
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private looksLikeUUID(samples: any[]): boolean {
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const uuidPattern = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
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return samples.every(v => {
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if (typeof v !== 'string') return false
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return uuidPattern.test(v.trim())
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})
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}
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// ============================================================================
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// Cache Management
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// ============================================================================
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/**
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* Load type info from persistent storage
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*/
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private async loadFromStorage(field: string): Promise<FieldTypeInfo | null> {
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try {
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const cacheKey = `${this.CACHE_STORAGE_PREFIX}${field}`
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const data = await this.storage.getMetadata(cacheKey)
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if (data) {
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// Double cast for type boundary crossing
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return data as unknown as FieldTypeInfo
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}
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} catch (error) {
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prodLog.debug(`Failed to load field type cache for '${field}':`, error)
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}
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return null
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}
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/**
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* Save type info to both in-memory and persistent cache
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*/
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private async saveToCache(field: string, typeInfo: FieldTypeInfo): Promise<void> {
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// Save to in-memory cache
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this.typeCache.set(field, typeInfo)
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// Save to persistent storage (async, non-blocking)
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// Add required 'noun' property for NounMetadata
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const cacheKey = `${this.CACHE_STORAGE_PREFIX}${field}`
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const metadataObj = {
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noun: 'FieldTypeCache',
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...typeInfo
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}
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await this.storage.saveMetadata(cacheKey, metadataObj as any).catch(error => {
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prodLog.warn(`Failed to save field type cache for '${field}':`, error)
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})
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}
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/**
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* Check if cached type info is still fresh
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*
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* Cache is considered fresh if:
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* - High confidence (>= 0.9)
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* - Updated within last 24 hours
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* - Analyzed at least 50 samples
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*/
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private isCacheFresh(typeInfo: FieldTypeInfo): boolean {
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const age = Date.now() - typeInfo.lastUpdated
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return (
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typeInfo.confidence >= 0.9 &&
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age < this.CACHE_AGE_THRESHOLD &&
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typeInfo.sampleSize >= this.MIN_SAMPLE_SIZE_FOR_CONFIDENCE
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)
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}
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/**
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* Progressive refinement: Update type inference as more data arrives
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*
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* This is called when we have more samples and want to improve confidence.
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* Only updates cache if confidence improves.
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*/
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async refineTypeInference(field: string, newValues: any[]): Promise<void> {
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const current = await this.loadFromStorage(field)
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if (!current) return
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// Analyze with new samples
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const refined = await this.analyzeValues(field, newValues)
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// Only update if confidence improved or sample size increased significantly
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if (
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refined.confidence > current.confidence ||
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refined.sampleSize > current.sampleSize * 2
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) {
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await this.saveToCache(field, refined)
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}
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}
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/**
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* Check if a field type is temporal
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*/
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isTemporal(type: FieldType): boolean {
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return [
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FieldType.TIMESTAMP_MS,
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FieldType.TIMESTAMP_S,
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FieldType.DATE_ISO8601,
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FieldType.DATETIME_ISO8601
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].includes(type)
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}
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|
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/**
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* Get bucket size for a temporal field type
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*/
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getBucketSize(typeInfo: FieldTypeInfo): number {
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if (!this.isTemporal(typeInfo.inferredType)) {
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return 0
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}
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return typeInfo.metadata?.bucketSize || 60000 // Default: 1 minute
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}
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|
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/**
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* Clear cache for a field (useful for testing)
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*/
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async clearCache(field?: string): Promise<void> {
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if (field) {
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this.typeCache.delete(field)
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const cacheKey = `${this.CACHE_STORAGE_PREFIX}${field}`
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// null signals deletion to storage adapter
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await this.storage.saveMetadata(cacheKey, null as any)
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} else {
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this.typeCache.clear()
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}
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}
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|
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/**
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* Get cache statistics for monitoring
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*/
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getCacheStats(): {
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size: number
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fields: string[]
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temporalFields: number
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nonTemporalFields: number
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} {
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const fields = Array.from(this.typeCache.keys())
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const temporalFields = Array.from(this.typeCache.values()).filter(info =>
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this.isTemporal(info.inferredType)
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).length
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return {
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size: this.typeCache.size,
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fields,
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temporalFields,
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nonTemporalFields: this.typeCache.size - temporalFields
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}
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}
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// ============================================================================
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// Helper Methods
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// ============================================================================
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|
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/**
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|
* Create a FieldTypeInfo object
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*/
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private createTypeInfo(
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field: string,
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type: FieldType,
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confidence: number,
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sampleSize: number,
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|
format: string,
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|
extraMetadata?: Record<string, any>
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|
): FieldTypeInfo {
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return {
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field,
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inferredType: type,
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confidence,
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sampleSize,
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lastUpdated: Date.now(),
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detectionMethod: 'value',
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metadata: {
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format,
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|
...extraMetadata
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}
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|
}
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}
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|
}
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