Metadata Filtering Strategy

As a Lead AI Engineer, design a metadata filtering strategy for vector search.

## Document Metadata Schema
{{metadata_schema}}

## Common Query Filters
{{common_filters}}

## Performance Requirements
- Filter evaluation: < {{filter_latency}}ms
- Combined with vector search: < {{total_latency}}ms

Analyze filtering approaches:

**Approach 1: Pre-filtering**
- When to use
- Index requirements
- Performance implications

**Approach 2: Post-filtering**
- When to use
- Over-fetch strategies
- Result consistency

**Approach 3: Hybrid filtering**
- Implementation details
- Trade-offs

Provide:
- Decision framework for filter strategy selection
- Index design recommendations
- Query optimization techniques
- Monitoring for filter effectiveness