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# 第四节 智能查询路由与检索策略
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> 不同类型的查询需要不同的检索策略。本节将详细介绍如何构建智能查询路由器,实现查询复杂度分析和检索策略的自动选择,以及三种核心检索策略的设计与实现。
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## 一、智能查询路由器设计
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### 1.1 查询路由的必要性
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在图RAG系统中,可以实现更多样化的查询类型:
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**简单查询**:
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- "川菜有哪些?"
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- "宫保鸡丁怎么做?"
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- "减肥菜推荐"
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**复杂推理查询**:
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- "适合糖尿病人吃的低糖川菜有哪些,并且制作时间不超过30分钟?"
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- "如果我只有鸡肉和蔬菜,能做什么菜,最好是不同菜系的?"
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- "哪些菜可以用豆腐替代肉类,并且保持相似的口感?"
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**中等复杂查询**:
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- "家常菜中哪些适合新手制作?"
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- "有什么菜可以用剩余的土豆和胡萝卜?"
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不同复杂度的查询需要不同的检索策略来获得最佳效果。
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### 1.2 查询分析框架
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智能查询路由器通过四个维度分析查询特征:
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```python
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class IntelligentQueryRouter:
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def __init__(self, traditional_retrieval, graph_rag_retrieval, llm_client, config):
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self.traditional_retrieval = traditional_retrieval
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self.graph_rag_retrieval = graph_rag_retrieval
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self.llm_client = llm_client
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self.config = config
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# 路由统计
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self.route_stats = {
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"traditional_count": 0,
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"graph_rag_count": 0,
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"combined_count": 0,
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"total_queries": 0
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}
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def analyze_query(self, query: str) -> QueryAnalysis:
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"""深度分析查询特征,决定最佳检索策略"""
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analysis_prompt = f"""
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作为RAG系统的查询分析专家,请深度分析以下查询的特征:
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查询:{query}
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请从以下维度分析:
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1. 查询复杂度 (0-1):
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- 0.0-0.3: 简单信息查找(如:红烧肉怎么做?)
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- 0.4-0.7: 中等复杂度(如:川菜有哪些特色菜?)
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- 0.8-1.0: 高复杂度推理(如:为什么川菜用花椒而不是胡椒?)
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2. 关系密集度 (0-1):
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- 0.0-0.3: 单一实体信息(如:西红柿的营养价值)
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- 0.4-0.7: 实体间关系(如:鸡肉配什么蔬菜?)
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- 0.8-1.0: 复杂关系网络(如:川菜的形成与地理、历史的关系)
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3. 推理需求:是否需要多跳推理、因果分析、对比分析?
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4. 实体识别:查询中包含多少个明确实体?
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基于分析推荐检索策略:
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- hybrid_traditional: 适合简单直接的信息查找
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- graph_rag: 适合复杂关系推理和知识发现
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- combined: 需要两种策略结合
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返回JSON格式:
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{{
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"query_complexity": 0.6,
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"relationship_intensity": 0.8,
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"reasoning_required": true,
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"entity_count": 3,
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"recommended_strategy": "graph_rag",
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"confidence": 0.85,
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"reasoning": "该查询涉及多个实体间的复杂关系,需要图结构推理"
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}}
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"""
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try:
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response = self.llm_client.chat.completions.create(
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model=self.config.llm_model,
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messages=[{"role": "user", "content": analysis_prompt}],
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temperature=0.1,
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max_tokens=800
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)
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result = json.loads(response.choices[0].message.content.strip())
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# 构建QueryAnalysis对象
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analysis = QueryAnalysis(
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query_complexity=result.get("query_complexity", 0.5),
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relationship_intensity=result.get("relationship_intensity", 0.5),
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reasoning_required=result.get("reasoning_required", False),
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entity_count=result.get("entity_count", 1),
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recommended_strategy=SearchStrategy(result.get("recommended_strategy", "hybrid_traditional")),
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confidence=result.get("confidence", 0.5),
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reasoning=result.get("reasoning", "默认分析")
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)
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return analysis
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except Exception as e:
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logger.error(f"查询分析失败: {e}")
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# 降级方案:基于规则的简单分析
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return self._rule_based_analysis(query)
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```
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### 1.3 规则基础的降级分析
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当LLM分析失败时,使用基于规则的降级分析:
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```python
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def _rule_based_analysis(self, query: str) -> QueryAnalysis:
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"""基于规则的降级分析"""
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# 简单的规则判断
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complexity_keywords = ["为什么", "如何", "关系", "影响", "原因", "比较", "区别"]
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relation_keywords = ["配", "搭配", "组合", "相关", "联系", "连接"]
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complexity = sum(1 for kw in complexity_keywords if kw in query) / len(complexity_keywords)
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relation_intensity = sum(1 for kw in relation_keywords if kw in query) / len(relation_keywords)
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# 策略选择
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if complexity > 0.3 or relation_intensity > 0.3:
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strategy = SearchStrategy.GRAPH_RAG
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else:
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strategy = SearchStrategy.HYBRID_TRADITIONAL
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return QueryAnalysis(
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query_complexity=complexity,
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relationship_intensity=relation_intensity,
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reasoning_required=complexity > 0.3,
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entity_count=len(query.split()), # 简单估算
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recommended_strategy=strategy,
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confidence=0.6,
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reasoning="基于规则的简单分析"
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)
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```
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### 1.4 智能路由执行
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基于分析结果,路由到最适合的检索策略:
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```python
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def route_query(self, query: str, top_k: int = 5) -> Tuple[List[Document], QueryAnalysis]:
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"""智能路由查询到最适合的检索引擎"""
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logger.info(f"开始智能路由: {query}")
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# 1. 分析查询特征
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analysis = self.analyze_query(query)
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# 2. 更新统计
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self._update_route_stats(analysis.recommended_strategy)
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# 3. 根据策略执行检索
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try:
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if analysis.recommended_strategy == SearchStrategy.HYBRID_TRADITIONAL:
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logger.info("使用传统混合检索")
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documents = self.traditional_retrieval.hybrid_search(query, top_k)
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elif analysis.recommended_strategy == SearchStrategy.GRAPH_RAG:
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logger.info("🕸️ 使用图RAG检索")
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documents = self.graph_rag_retrieval.graph_rag_search(query, top_k)
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elif analysis.recommended_strategy == SearchStrategy.COMBINED:
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logger.info("🔄 使用组合检索策略")
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documents = self._combined_search(query, top_k)
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# 4. 结果后处理
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documents = self._post_process_results(documents, analysis)
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return documents, analysis
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except Exception as e:
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logger.error(f"查询路由失败: {e}")
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# 降级到传统检索
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documents = self.traditional_retrieval.hybrid_search(query, top_k)
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return documents, analysis
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def _combined_search(self, query: str, top_k: int) -> List[Document]:
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"""组合搜索策略:结合传统检索和图RAG的优势"""
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# 分配结果数量
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traditional_k = max(1, top_k // 2)
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graph_k = top_k - traditional_k
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# 执行两种检索
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traditional_docs = self.traditional_retrieval.hybrid_search(query, traditional_k)
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graph_docs = self.graph_rag_retrieval.graph_rag_search(query, graph_k)
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# 合并和去重(简化实现)
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# ... 具体的合并逻辑
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return combined_docs
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```
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## 二、三种检索策略详解
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### 2.1 传统混合检索策略
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> [混合检索模块代码](https://github.com/datawhalechina/all-in-rag/blob/main/code/C9/rag_modules/hybrid_retrieval.py)
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适用于简单查询,结合双层检索和向量检索:
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```python
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class HybridRetrievalModule:
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def hybrid_search(self, query: str, top_k: int = 5) -> List[Document]:
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"""
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混合检索:使用Round-robin轮询合并策略
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公平轮询合并不同检索结果,不使用权重配置
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"""
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logger.info(f"开始混合检索: {query}")
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# 1. 双层检索(实体+主题检索)
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dual_docs = self.dual_level_retrieval(query, top_k)
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# 2. 增强向量检索
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vector_docs = self.vector_search_enhanced(query, top_k)
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# 3. Round-robin轮询合并
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merged_docs = []
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seen_doc_ids = set()
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max_len = max(len(dual_docs), len(vector_docs))
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# Round-robin策略:交替从两个结果列表中取文档
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# 这种方法确保了不同检索方法的结果都能得到公平的展示机会
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for i in range(max_len):
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# 先添加双层检索结果
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if i < len(dual_docs):
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doc = dual_docs[i]
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doc_id = doc.metadata.get("node_id", hash(doc.page_content))
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if doc_id not in seen_doc_ids:
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seen_doc_ids.add(doc_id)
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doc.metadata["search_method"] = "dual_level"
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doc.metadata["final_score"] = doc.metadata.get("relevance_score", 0.0)
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merged_docs.append(doc)
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# 再添加向量检索结果
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if i < len(vector_docs):
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doc = vector_docs[i]
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doc_id = doc.metadata.get("node_id", hash(doc.page_content))
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if doc_id not in seen_doc_ids:
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seen_doc_ids.add(doc_id)
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doc.metadata["search_method"] = "vector"
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doc.metadata["final_score"] = doc.metadata.get("relevance_score", 0.0)
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merged_docs.append(doc)
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return merged_docs[:top_k]
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```
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**Round-robin轮询合并原理**:Round-robin(轮询)是一种公平调度算法,在RAG系统中用于融合多个检索结果。其核心是按顺序轮流从不同的结果列表中选择文档,而不是基于分数权重进行合并。这种方法确保了每种检索策略的结果都能得到公平的展示机会,避免了某种方法因排序靠前而被过度选择的问题。相比复杂的加权融合,Round-robin实现简单且稳定,无需调优权重参数,自然保持了结果的多样性。
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### 2.2 图RAG检索策略
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> [图RAG检索模块代码](https://github.com/datawhalechina/all-in-rag/blob/main/code/C9/rag_modules/graph_rag_retrieval.py)
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适用于复杂推理查询,基于图结构进行多跳推理:
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```python
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class GraphRAGRetrieval:
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def graph_rag_search(self, query: str, top_k: int = 5) -> List[Document]:
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"""
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图RAG主搜索接口:整合所有图RAG能力
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"""
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logger.info(f"开始图RAG检索: {query}")
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# 1. 查询意图理解
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graph_query = self.understand_graph_query(query)
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logger.info(f"查询类型: {graph_query.query_type.value}")
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results = []
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try:
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# 2. 根据查询类型执行不同策略
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if graph_query.query_type in [QueryType.MULTI_HOP, QueryType.PATH_FINDING]:
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# 多跳遍历
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paths = self.multi_hop_traversal(graph_query)
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results.extend(self._paths_to_documents(paths, query))
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elif graph_query.query_type == QueryType.SUBGRAPH:
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# 子图提取
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subgraph = self.extract_knowledge_subgraph(graph_query)
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# 图结构推理
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reasoning_chains = self.graph_structure_reasoning(subgraph, query)
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results.extend(self._subgraph_to_documents(subgraph, reasoning_chains, query))
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elif graph_query.query_type == QueryType.ENTITY_RELATION:
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# 实体关系查询
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paths = self.multi_hop_traversal(graph_query)
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results.extend(self._paths_to_documents(paths, query))
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# 3. 图结构相关性排序
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results = self._rank_by_graph_relevance(results, query)
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return results[:top_k]
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except Exception as e:
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logger.error(f"图RAG检索失败: {e}")
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return []
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```
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**图RAG检索流程**:
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```mermaid
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flowchart TD
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A[用户查询] --> B[查询意图理解]
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B --> C{查询类型判断}
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C -->|简单关系| D1[实体关系查询]
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C -->|复杂推理| D2[多跳推理查询]
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C -->|知识网络| D3[子图提取查询]
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D1 --> E1[直接关系检索]
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D2 --> E2[多跳图遍历]
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D3 --> E3[知识子图提取]
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E1 --> F[结果转换与排序]
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E2 --> F
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E3 --> F
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F --> G[返回Top-K结果]
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style A fill:#e1f5fe
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style C fill:#fff3e0
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style F fill:#f3e5f5
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style G fill:#e8f5e8
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```
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**多跳推理**:
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多跳推理是指通过图中的多个节点和关系进行间接推理,这是图RAG相比传统RAG的核心优势。传统检索只能找到直接匹配的信息,而多跳推理能够发现数据中的隐含关联。
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- **工作原理**:
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1. **路径发现**:在知识图谱中寻找连接起始实体和目标实体的路径
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2. **关系传递**:通过中间节点传递语义关系
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3. **隐含推理**:发现原始数据中没有明确表达的知识关联
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- **具体示例**:用户问"鸡肉配什么蔬菜好?"
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```
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传统检索:只能找到直接提到"鸡肉+蔬菜"的文档(可能很少)
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多跳推理:
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1跳:鸡肉 → 宫保鸡丁、口水鸡、白切鸡...
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2跳:宫保鸡丁 → 胡萝卜、青椒、花生米...
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3跳:胡萝卜 → 蔬菜类别
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推理结果:鸡肉经常与胡萝卜、青椒等蔬菜搭配
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```
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- **多跳推理的价值**:
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- **知识发现**:挖掘数据中的隐含关系
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- **推荐增强**:提供更丰富的搭配建议
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- **语义理解**:模拟人类的联想思维过程
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- **数据利用**:充分利用图结构的关系信息
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通过这种多跳遍历,系统能发现"鸡肉"和"胡萝卜"之间的隐含关系:它们经常在同一道菜中出现,即使在原始数据中没有直接的"鸡肉-胡萝卜"关系。
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### 2.3 组合检索策略
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> [智能查询路由器代码](https://github.com/datawhalechina/all-in-rag/blob/main/code/C9/rag_modules/intelligent_query_router.py)
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适用于中等复杂查询,结合传统检索和图RAG的优势:
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```python
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def _combined_search(self, query: str, top_k: int) -> List[Document]:
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"""组合搜索策略:结合传统检索和图RAG的优势"""
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# 分配结果数量
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traditional_k = max(1, top_k // 2)
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graph_k = top_k - traditional_k
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||||
|
||||
# 执行两种检索
|
||||
traditional_docs = self.traditional_retrieval.hybrid_search(query, traditional_k)
|
||||
graph_docs = self.graph_rag_retrieval.graph_rag_search(query, graph_k)
|
||||
|
||||
# Round-robin轮询合并(参考LightRAG的融合策略)
|
||||
combined_docs = []
|
||||
seen_contents = set()
|
||||
|
||||
# 交替添加结果,保持多样性(Round-robin策略)
|
||||
max_len = max(len(traditional_docs), len(graph_docs))
|
||||
for i in range(max_len):
|
||||
# 添加传统检索结果
|
||||
if i < len(traditional_docs):
|
||||
doc = traditional_docs[i]
|
||||
if doc.page_content not in seen_contents:
|
||||
seen_contents.add(doc.page_content)
|
||||
doc.metadata["search_strategy"] = "traditional"
|
||||
combined_docs.append(doc)
|
||||
|
||||
# 添加图RAG结果
|
||||
if i < len(graph_docs):
|
||||
doc = graph_docs[i]
|
||||
if doc.page_content not in seen_contents:
|
||||
seen_contents.add(doc.page_content)
|
||||
doc.metadata["search_strategy"] = "graph_rag"
|
||||
combined_docs.append(doc)
|
||||
|
||||
return combined_docs[:top_k]
|
||||
```
|
||||
|
||||
**Round-robin轮询合并机制**:在组合检索中,Round-robin算法按照固定的轮转顺序从传统检索和图RAG检索的结果中交替选择文档。具体过程是:第1个位置选择传统检索的第1个结果,第2个位置选择图RAG的第1个结果,第3个位置选择传统检索的第2个结果,以此类推。这种机制避免了复杂的分数融合计算,通过位置轮转自然实现了不同检索策略结果的均衡分布,是一种简单而有效的多源信息融合方法。
|
||||
|
||||
## 三、路由决策逻辑
|
||||
|
||||
智能查询路由器通过分析查询特征,自动选择最适合的检索策略:
|
||||
|
||||
**决策规则**:
|
||||
- **简单查询**(复杂度 < 0.4)→ 传统混合检索
|
||||
- **复杂推理查询**(复杂度 > 0.7 或关系密集度 > 0.7)→ 图RAG检索
|
||||
- **中等复杂查询**(0.4 ≤ 复杂度 ≤ 0.7)→ 组合检索策略
|
||||
|
||||
**路由统计与优化**:
|
||||
|
||||
```python
|
||||
def _update_route_stats(self, strategy: SearchStrategy):
|
||||
"""更新路由统计信息"""
|
||||
self.route_stats["total_queries"] += 1
|
||||
if strategy == SearchStrategy.HYBRID_TRADITIONAL:
|
||||
self.route_stats["traditional_count"] += 1
|
||||
elif strategy == SearchStrategy.GRAPH_RAG:
|
||||
self.route_stats["graph_rag_count"] += 1
|
||||
elif strategy == SearchStrategy.COMBINED:
|
||||
self.route_stats["combined_count"] += 1
|
||||
```
|
||||
|
||||
> 最后的生成部分就不过多赘述了,和第八章类似,可以自行查阅代码。本章项目并不完善,仅作为对 GraphRAG 流程和架构的理解。可根据前面所学内容自行优化。
|
||||
>
|
||||
> [What-to-eat-today 给当前项目加个前端并做了点优化,可以参考](https://github.com/FutureUnreal/What-to-eat-today)
|
||||
Reference in New Issue
Block a user