Module optimizer_integration 

Query Optimizer Integration (Task 10)

Wires the QueryOptimizer into the SOCH-QL execution path for cost-based planning:

• Converts SOCH-QL WHERE clauses to optimizer predicates
• Uses cardinality hints from HyperLogLog sketches
• Selects optimal index based on selectivity estimates

Integration Flow

SOCH-QL Query
    │
    ▼
┌─────────────────┐
│ Parse & Validate│
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ Extract         │
│ Predicates      │ ← WHERE clause → QueryPredicate[]
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ QueryOptimizer  │
│ .plan_query()   │ ← Cost-based index selection
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ Execute Plan    │
└─────────────────┘

Task 11: HyperLogLog Integration for Real-Time Cardinality

The CardinalityTracker maintains HyperLogLog sketches per column for real-time cardinality estimation with <1% standard error.

On INSERT:
  tracker.observe("column_name", value)  // O(1) HLL update

On SELECT planning:
  cardinality = tracker.estimate("column_name")  // O(1) estimate

Math:
  Standard error = 1.04 / sqrt(m) where m = 2^precision
  For precision=14: SE = 0.81%, memory = 16KB per column

Structs

AdaptiveCacheStats

Enhanced cache statistics

CacheStats

Cache statistics

CardinalityEstimate

Cardinality estimate with confidence

CardinalityTracker

Real-time cardinality tracker using HyperLogLog sketches

CardinalityTrackerStats

Statistics for cardinality tracker

ExecutionPlan

Execution plan with ordered steps

OptimizedExecutor

Optimized query executor with cost-based planning

OptimizedQueryPlan

Optimized query plan with cost estimates

PlanCache

Query plan cache for repeated queries

TableStats

Statistics for a table

Enums

ExecutionStep

Single execution step

Traits

StorageBackend

Storage backend trait for executing optimized query plans