[Feature Request] <title> Supporting fp16 vector indexing without using the faiss encoder

[ehsankf]

Is your feature request related to a problem? Please describe

Is there any specific data_type in OpenSearch to support indexing fp16 vector indexing? This would help to avoid indexing the original fp32 vectors and reduce the disk size. This feature is supported for binary and byte data types.

Describe the solution you'd like

Adding a data_type to support fp16 vector indexing without needing to real-time transformation using encode API

Related component

Indexing

Describe alternatives you've considered

No response

Additional context

No response

[coderabbitai]

📝 CodeRabbit Plan Mode

Generate an implementation plan and prompts that you can use with your favorite coding agent.

• Create Plan

Examples

• Example 1
• Example 2

---

🧪 Issue enrichment is currently in open beta.

You can configure auto-planning by selecting labels in the issue_enrichment configuration.

To disable automatic issue enrichment, add the following to your .coderabbit.yaml:

issue_enrichment:
  auto_enrich:
    enabled: false

💬 Have feedback or questions? Drop into our discord!