refactor: 移除 PostgreSQL 支持，简化为纯 SQLite 部署
- config.py: DATABASE_URL 默认值改为 SQLite - database.py: 移除 PostgreSQL 分支，简化为纯 SQLite - models/base.py: 移除 pgvector 导入和条件分支 - search_service.py: 移除 _search_postgres 方法 - import_service.py: 移除 pgvector 相关代码 - requirements.txt: 移除 asyncpg/alembic/pgvector 依赖 - pyproject.toml: 同步移除相关依赖 - docker-compose.yml: 移除 db 服务，- 删除 alembic.ini/Dockerfile.db/sql 目录 - README.md: 更新文档，移除 PostgreSQL 相关内容 适合 NAS 等资源受限环境的轻量级部署
This commit is contained in:
EduBrain Dev
@@ -1,20 +1,18 @@
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"""
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语义搜索服务
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支持 PostgreSQL（向量+全文混合）和 SQLite（LIKE 关键词搜索）
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SQLite 数据库，使用 LIKE 关键词搜索。
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"""
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from __future__ import annotations
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import json
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import logging
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import time
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from typing import List, Optional
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from typing import List
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from sqlalchemy import text
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from sqlalchemy.ext.asyncio import AsyncSession
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from app.config import settings
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from app.database import IS_SQLITE
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from app.schemas.search import SearchRequest, SearchResult, SearchResponse
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logger = logging.getLogger(__name__)
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@@ -28,21 +26,10 @@ class SearchService:
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async def search(self, request: SearchRequest) -> SearchResponse:
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"""
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执行搜索。
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- PostgreSQL: 向量搜索 + 中文全文搜索混合排序
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- SQLite: LIKE 关键词搜索（无向量能力）
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执行搜索：使用 LIKE 关键词搜索
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"""
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start_time = time.time()
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if IS_SQLITE:
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return await self._search_sqlite(request, start_time)
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else:
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return await self._search_postgres(request, start_time)
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# ──────────────────────────── SQLite 搜索 ────────────────────────────
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async def _search_sqlite(self, request: SearchRequest, start_time: float) -> SearchResponse:
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"""SQLite 模式：使用 LIKE 关键词搜索"""
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# LLM 查询扩展（可选）
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expanded_queries = [request.query]
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try:
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@@ -109,178 +96,3 @@ class SearchService:
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results=results,
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elapsed_ms=round(elapsed_ms, 2),
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)
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# ──────────────────────────── PostgreSQL 搜索 ────────────────────────────
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async def _search_postgres(self, request: SearchRequest, start_time: float) -> SearchResponse:
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"""PostgreSQL 模式：向量搜索 + 中文全文搜索混合"""
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# LLM 查询扩展
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expanded_queries = [request.query]
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if request.use_fulltext:
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try:
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from app.services.llm_service import LLMService
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expanded_queries = await LLMService.expand_query(request.query)
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except Exception as exc:
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logger.debug("查询扩展跳过: %s", exc)
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# 生成查询向量
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from app.services.embedding_service import EmbeddingService
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all_query_embeddings = await EmbeddingService.embed_batch(expanded_queries)
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# 构建过滤条件
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where_clauses = []
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params: dict = {}
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if request.course_name:
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where_clauses.append("kp.course_name = :course_name")
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params["course_name"] = request.course_name
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if request.teacher_name:
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where_clauses.append("kp.teacher_name = :teacher_name")
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params["teacher_name"] = request.teacher_name
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if request.live_date_from:
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where_clauses.append("kp.live_date >= :live_date_from")
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params["live_date_from"] = request.live_date_from
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if request.live_date_to:
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where_clauses.append("kp.live_date <= :live_date_to")
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params["live_date_to"] = request.live_date_to
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where_sql = ""
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if where_clauses:
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where_sql = "AND " + " AND ".join(where_clauses)
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# 向量搜索
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vector_results = []
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params["limit"] = request.top_k * 2
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for q_embedding in all_query_embeddings:
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embedding_str = "[" + ",".join(str(x) for x in q_embedding) + "]"
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vector_sql = f"""
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SELECT
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kc.id AS chunk_id,
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kp.id AS page_id,
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kp.title AS page_title,
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kc.content,
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1 - (kc.embedding <=> :embedding::vector) AS vector_score,
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0.0 AS text_score,
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kp.course_name,
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kp.teacher_name,
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kp.live_date
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FROM knowledge_chunks kc
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JOIN knowledge_pages kp ON kc.page_id = kp.id
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WHERE kc.embedding IS NOT NULL
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{where_sql}
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ORDER BY kc.embedding <=> :embedding::vector
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LIMIT :limit
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"""
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v_params = {**params, "embedding": embedding_str}
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result = await self.db.execute(text(vector_sql), v_params)
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vector_results.extend(result.fetchall())
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# 全文搜索
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text_results = []
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if request.use_fulltext:
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for q in expanded_queries:
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clean_query = q.replace("'", "''")
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fulltext_sql = f"""
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SELECT
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kc.id AS chunk_id,
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kp.id AS page_id,
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kp.title AS page_title,
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kc.content,
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0.0 AS vector_score,
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ts_rank_cd(kc.search_vector, to_tsquery('chinese_zh', :query)) AS text_score,
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kp.course_name,
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kp.teacher_name,
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kp.live_date,
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ts_headline('chinese_zh', kc.content, to_tsquery('chinese_zh', :query),
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'MaxWords=50, MinWords=20, ShortWord=2') AS highlight
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FROM knowledge_chunks kc
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JOIN knowledge_pages kp ON kc.page_id = kp.id
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WHERE kc.search_vector @@ to_tsquery('chinese_zh', :query)
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{where_sql}
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ORDER BY text_score DESC
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LIMIT :limit
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"""
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ft_params = {**params, "query": clean_query}
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ft_result = await self.db.execute(text(fulltext_sql), ft_params)
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text_results.extend(ft_result.fetchall())
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# 合并结果
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merged: dict[int, dict] = {}
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for row in vector_results:
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chunk_id = row.chunk_id
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if chunk_id not in merged:
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merged[chunk_id] = {
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"chunk_id": chunk_id,
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"page_id": row.page_id,
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"page_title": row.page_title,
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"content": row.content,
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"vector_score": row.vector_score,
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"text_score": 0.0,
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"course_name": row.course_name,
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"teacher_name": row.teacher_name,
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"live_date": row.live_date,
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"highlight": None,
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}
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else:
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merged[chunk_id]["vector_score"] = max(
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merged[chunk_id]["vector_score"], row.vector_score
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)
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for row in text_results:
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chunk_id = row.chunk_id
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if chunk_id not in merged:
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merged[chunk_id] = {
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"chunk_id": chunk_id,
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"page_id": row.page_id,
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"page_title": row.page_title,
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"content": row.content,
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"vector_score": 0.0,
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"text_score": row.text_score or 0.0,
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"course_name": row.course_name,
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"teacher_name": row.teacher_name,
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"live_date": row.live_date,
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"highlight": row.highlight,
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}
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else:
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merged[chunk_id]["text_score"] = max(
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merged[chunk_id]["text_score"], row.text_score or 0.0
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)
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if row.highlight:
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merged[chunk_id]["highlight"] = row.highlight
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# 计算综合得分
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max_text_score = max(
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(r["text_score"] for r in merged.values()), default=1.0
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) or 1.0
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scored_results = []
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for item in merged.values():
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normalized_text = item["text_score"] / max_text_score if max_text_score > 0 else 0
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combined_score = 0.7 * item["vector_score"] + 0.3 * normalized_text
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if combined_score >= request.threshold:
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scored_results.append(
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SearchResult(
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chunk_id=item["chunk_id"],
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page_id=item["page_id"],
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page_title=item["page_title"],
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content=item["content"],
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score=round(combined_score, 4),
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course_name=item["course_name"],
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teacher_name=item["teacher_name"],
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live_date=item["live_date"],
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highlight=item["highlight"],
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)
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)
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scored_results.sort(key=lambda x: x.score, reverse=True)
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scored_results = scored_results[:request.top_k]
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elapsed_ms = (time.time() - start_time) * 1000
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return SearchResponse(
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query=request.query,
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total=len(scored_results),
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results=scored_results,
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elapsed_ms=round(elapsed_ms, 2),
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)
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