Logical Views: Virtual indices you can query like any other index in ES|QL (GA)

## Value Proposition

A logical view is a virtual index — an ES|QL query stored at the Elasticsearch cluster level and referenced by name in `FROM`, just like any other index. Consumers don't need to know the underlying logic; Elasticsearch resolves it like any other index at query time.

This brings the virtual-index abstraction that SQL databases have had for decades into the search, observability, and security domain. Where other tools stop at saved searches or UI-level presets, ES|QL views are engine-level, first-class virtual indices with composition and update propagation — source teams define base views, platform teams compose them, and consumers simply query a name.

## Expected Outcome

Logical Views shipped in Tech Preview in Elasticsearch 9.4, where users can create views via REST API and query them from the FROM clause like any other index.

For GA, we are bringing Logical Views to production readiness. Scope is being refined based on tech preview feedback; potential areas include:

- **Cross-Project Search support:** views work across remote clusters, honoring the flat-world principle with proper project routing isolation
- **Query parameters:** views accept parameters, enabling reusable templates that consumers can customize at query time
- **Deep composition:** support for nested views and branched view definitions (including FORK/UnionAll)
- **Data Federation:** views can be defined over federated data sources
- **Query DSL compatibility:** filters applied via Query DSL work correctly on views
- **Production stability:** bug fixes, expanded test coverage, and validation under real-world workloads