> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/client-interfaces/information-schema/infoschema-sql-sizing.md).

# 35.51. sql\_sizing \#

資料表 `sql_sizing` 包含 PostgreSQL 中各種大小限制與最大值的資訊。此資訊主要 供 ODBC 介面使用；其他介面的使用者可能很少需要使用。因此，這裡不會說明個別的 大小項目；請參閱 ODBC 介面的說明。

**表 35.49. `sql_sizing` 欄位**

| <p>欄位類型</p><p>說明</p>                                                                                                   |
| ---------------------------------------------------------------------------------------------------------------------- |
| <p><code>sizing\_id</code> <code>cardinal\_number</code></p><p>大小項目的識別字</p>                                            |
| <p><code>sizing\_name</code> <code>character\_data</code></p><p>大小項目的描述性名稱</p>                                         |
| <p><code>supported\_value</code> <code>cardinal\_number</code></p><p>大小項目的值；若大小無限制或無法判定則為 0；若不支援適用此大小項目的 功能則為 null</p> |
| <p><code>comments</code> <code>character\_data</code></p><p>可能與大小項目相關的註解</p>                                           |

<br>

***

【[PostgreSQL 18.6 文件](https://www.postgresql.org/docs/18/infoschema-sql-sizing.html)】


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://docs.postgresql.tw/client-interfaces/information-schema/infoschema-sql-sizing.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.