# PostgreSQL 9.1 → 9.2 GUC 差异

> PG9.1 与 PG9.2 之间新增、boot 默认值变化和移除的核心配置参数。
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> [!NOTE]
> **Fact。** 实测在档数从 219 变为 224；新增 8、boot 默认值变化 4、移除 3。

## 新增参数 {#added}

| 参数 | 类型 | Context | Boot 默认值 | 分类 |
| --- | --- | --- | --- | --- |
| [`enable_indexonlyscan`](/zh/parameters/enable-indexonlyscan/) | `bool` | `user` | `on` | Query Tuning / Planner Method Configuration |
| [`event_source`](/zh/parameters/event-source/) | `string` | `postmaster` | `PostgreSQL` | Reporting and Logging / Where to Log |
| [`ssl_ca_file`](/zh/parameters/ssl-ca-file/) | `string` | `postmaster` | `""` (empty string) | Connections and Authentication / Security and Authentication |
| [`ssl_cert_file`](/zh/parameters/ssl-cert-file/) | `string` | `postmaster` | `server.crt` | Connections and Authentication / Security and Authentication |
| [`ssl_crl_file`](/zh/parameters/ssl-crl-file/) | `string` | `postmaster` | `""` (empty string) | Connections and Authentication / Security and Authentication |
| [`ssl_key_file`](/zh/parameters/ssl-key-file/) | `string` | `postmaster` | `server.key` | Connections and Authentication / Security and Authentication |
| [`temp_file_limit`](/zh/parameters/temp-file-limit/) | `integer` | `superuser` | `-1 kB` | Resource Usage / Disk |
| [`track_io_timing`](/zh/parameters/track-io-timing/) | `bool` | `superuser` | `off` | Statistics / Query and Index Statistics Collector |
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## Boot 默认值变化 {#default-changes}

| 参数 | PG9.1 | PG9.2 | 分类 |
| --- | --- | --- | --- |
| [`TimeZone`](/zh/parameters/timezone/) | — (not set) | `GMT` | Client Connection Defaults / Locale and Formatting |
| [`log_timezone`](/zh/parameters/log-timezone/) | — (not set) | `GMT` | Reporting and Logging / What to Log |
| [`server_version`](/zh/parameters/server-version/) | `9.1.24` | `9.2.23` | Preset Options |
| [`server_version_num`](/zh/parameters/server-version-num/) | `90124` | `90223` | Preset Options |
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## 移除参数 {#removed}

| 参数 | 最后类型 | Context | 最后 Boot 默认值 | 分类 |
| --- | --- | --- | --- | --- |
| [`custom_variable_classes`](/zh/parameters/custom-variable-classes/) | `string` | `sighup` | — (not set) | Customized Options |
| [`silent_mode`](/zh/parameters/silent-mode/) | `bool` | `postmaster` | `off` | Reporting and Logging / Where to Log |
| [`wal_sender_delay`](/zh/parameters/wal-sender-delay/) | `integer` | `sighup` | `1000 ms` (1 s) | Replication / Master Server |
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## 计算方法 {#method}

三张清单直接比较固定环境中的 PG9.1 与 PG9.2 `pg_settings` 快照。默认值变化使用 `boot_val` 与 `unit` 的组合；`setting` 不参与判定，以免把 `initdb` 生成值误当作编译时默认值。

- [机器可读差异数据](/data/diffs.json)
- [完整 GUC JSONL](/data/guc.jsonl)