47 lines
930 B
Markdown
47 lines
930 B
Markdown
# 全文搜索引擎
|
|
|
|
具有 BM25 和 TF-IDF 排名的倒排索引。
|
|
|
|
## 用法
|
|
|
|
```nim
|
|
import barabadb/fts/engine
|
|
|
|
var idx = newInvertedIndex()
|
|
idx.addDocument(1, "Nim is a fast programming language")
|
|
idx.addDocument(2, "Python is popular for data science")
|
|
|
|
let results = idx.search("programming language")
|
|
let fuzzy = idx.fuzzySearch("programing", maxDistance = 2)
|
|
```
|
|
|
|
## 排名方法
|
|
|
|
### BM25
|
|
|
|
```nim
|
|
let bm25 = idx.searchBM25("query terms")
|
|
```
|
|
|
|
### TF-IDF
|
|
|
|
```nim
|
|
let tfidf = idx.searchTfidf("query terms")
|
|
```
|
|
|
|
## 搜索功能
|
|
|
|
| 功能 | 描述 |
|
|
|------|------|
|
|
| Fuzzy search | 允许拼写错误（Levenshtein 距离） |
|
|
| Wildcard | 前缀、后缀和中间通配符 |
|
|
| Regex | 正则表达式模式 |
|
|
| Phrase search | 精确短语匹配 |
|
|
| Boolean | AND、OR、NOT 运算符 |
|
|
|
|
## SQL 接口
|
|
|
|
```sql
|
|
CREATE INDEX idx_fts ON articles(body) USING FTS;
|
|
SELECT * FROM articles WHERE body @@ 'machine learning';
|
|
``` |