# F.6. btree\_gin

`btree_gin` provides sample GIN operator classes that implement B-tree equivalent behavior for the data types `int2`, `int4`, `int8`, `float4`, `float8`, `timestamp with time zone`, `timestamp without time zone`, `time with time zone`, `time without time zone`, `date`, `interval`, `oid`, `money`, `"char"`, `varchar`, `text`, `bytea`, `bit`, `varbit`, `macaddr`, `macaddr8`, `inet`, `cidr`, `uuid`, `name`, `bool`, `bpchar`, and all `enum` types.

通常，這些運算子類不會優於等效的標準 B-tree 索引方法，並且它們缺少標準 B-tree 的一個主要功能：強制執行唯一性。但是，它們對於 GIN 測試很有用，並且可以作為開發其他 GIN 運算子類的基礎。同樣地，對於同時測試可索引 GIN 欄位和 B-tree 可索引列的查詢，建立使用這些運算子之一的多欄位 GIN 索引可能比建立兩個必須獨立的索引更有效，以 bitmap ANDing 的方式。

## F.6.1. 使用範例

```
CREATE TABLE test (a int4);
-- create index
CREATE INDEX testidx ON test USING GIN (a);
-- query
SELECT * FROM test WHERE a < 10;
```

## F.6.2. 作者們

Teodor Sigaev (`<`[`teodor@stack.net`](mailto:teodor@stack.net)`>`) and Oleg Bartunov (`<`[`oleg@sai.msu.su`](mailto:oleg@sai.msu.su)`>`). See <http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gin> for additional information.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.postgresql.tw/13/appendixes/additional-supplied-modules/btree_gin.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.