https://github.com/milvus-io/milvus/issues/42589
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## Semantic Highlighting Feature
**Core Invariant**: Semantic highlighting operates on a per-field basis
with independent text processing through an external Zilliz highlight
provider. The implementation maintains field ID to field name mapping
and correlates highlight results back to original field outputs.
**What is Added**: This PR introduces semantic highlighting capability
for search results alongside the existing lexical highlighting. The
feature consists of:
- New `SemanticHighlight` orchestrator that validates queries/input
fields against collection schema, instantiates a Zilliz-based provider,
and batches text processing across multiple queries
- New `SemanticHighlighter` proxy wrapper implementing the `Highlighter`
interface for search pipeline integration
- New `semanticHighlightOperator` that processes search results by
delegating per-field text processing to the provider and attaching
correlated `HighlightResult` data to search outputs
- New gRPC service definition (`HighlightService`) and
`ZillizClient.Highlight()` method for external provider communication
**No Data Loss or Regression**: The change is purely additive without
modifying existing logic:
- Lexical highlighting path remains unchanged (separate switch case in
`createHighlightTask`)
- New `HighlightResults` field is only populated when semantic
highlighting is explicitly requested via `HighlightType_Semantic` enum
value
- Gracefully handles missing fields by returning explicit errors rather
than silent failures
- Pipeline operator integration follows existing patterns and only
processes when semantic highlighter is instantiated
**Why This Design**: Semantic highlighting is routed through the same
pipeline operator pattern as lexical highlighting, ensuring consistent
integration into search workflows. The per-field model allows flexible
highlighting across different text columns and batch processing ensures
efficient handling of multiple queries with configurable provider
constraints.
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Signed-off-by: junjie.jiang <junjie.jiang@zilliz.com>
relate: https://github.com/milvus-io/milvus/issues/46498
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- Core invariant: text fields configured with multi_analyzer_params must
include a "by_field" string that names another field containing per-row
analyzer choices; schemaInfo.GetMultiAnalyzerNameFieldID caches and
returns the dependent field ID (or 0 if none) and relies on that mapping
to make per-row analyzer names available to the highlighter.
- What changed / simplified: the highlighter is now schema-aware —
addTaskWithSearchText accepts *schemaInfo and uses
GetMultiAnalyzerNameFieldID to resolve the analyzer-name field;
resolution and caching moved into schemaInfo.multiAnalyzerFieldMap
(meta_cache.go), eliminating ad-hoc/typeutil-only lookups and duplicated
logic; GetMultiAnalyzerParams now gates on EnableAnalyzer(),
centralizing analyzer enablement checks.
- Why this fixes the bug (root cause): fixes#46498 — previously the
highlighter failed when the analyzer-by-field was not in output_fields.
The change (1) populates task.AnalyzerNames (defaulting missing names to
"default") when multi-analyzer is configured and (2) appends the
analyzer-name field ID to LexicalHighlighter.extraFields so FieldIDs
includes it; the operator then requests the analyzer-name column at
search time, ensuring per-row analyzer selection is available for
highlighting.
- No data-loss or regression: when no multi-analyzer is configured
GetMultiAnalyzerNameFieldID returns 0 and behavior is unchanged; the
patch only adds the analyzer-name field to requested output IDs (no
mutation of stored data). Error handling on malformed params is
preserved (errors are returned instead of silently changing data), and
single-analyzer behavior remains untouched.
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Signed-off-by: aoiasd <zhicheng.yue@zilliz.com>
Previously, search with highlight only supported using BM25 search text
as the highlight target.
This PR adds support for highlighting with user-defined queries.
relate: https://github.com/milvus-io/milvus/issues/42589
---------
Signed-off-by: aoiasd <zhicheng.yue@zilliz.com>
