weaviate/weaviate · error

SQ is not currently supported for flat indices

Error message

SQ is not currently supported for flat indices

What it means

Known limitation guard in flat index config parsing (marked TODO): scalar quantization (SQ) was requested for a flat index, but SQ is not yet implemented there. The check runs after the mutual-exclusion and RQ-bits checks in parseCompression, so a valid-but-unsupported SQ config reaches this error.

Source

Thrown at entities/vectorindex/flat/config.go:227

	}
	if uc.RQ.Enabled {
		totalEnabled++
		// Validate RQ bits
		if uc.RQ.Bits != 1 && uc.RQ.Bits != 8 {
			return errors.New("RQ bits must be either 1 or 8")
		}
	}

	if totalEnabled > 1 {
		return errors.New("cannot enable multiple quantization methods at the same time")
	}

	// TODO: remove once PQ and SQ are supported
	if uc.PQ.Enabled {
		return errors.New("PQ is not currently supported for flat indices")
	}
	if uc.SQ.Enabled {
		return errors.New("SQ is not currently supported for flat indices")
	}

	return nil
}

func parseRQConfig(in interface{}, rq *RQUserConfig) error {
	configMap, ok := in.(map[string]interface{})
	if ok {
		if err := vectorindexcommon.OptionalBoolFromMap(configMap, "enabled", func(v bool) {
			rq.Enabled = v
		}); err != nil {
			return err
		}

		if err := vectorindexcommon.OptionalBoolFromMap(configMap, "cache", func(v bool) {
			rq.Cache = v
		}); err != nil {
			return err

View on GitHub (pinned to 75aa4b6d11)

Solutions

1. Use BQ or RQ compression, which are supported on flat indices
2. Switch the collection to an HNSW index if SQ is required
3. Disable quantization for the flat index

When it happens

Trigger: Thrown at entities/vectorindex/flat/config.go:227 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of weaviate/weaviate@75aa4b6d11 (2026-09-04). Data as JSON: /api/errors/45d9f6f6b4927d10. Report an issue: GitHub.