# PostgreSQL 9.2 → 9.3 GUC diff

> Core configuration parameters added, removed, or changed in boot default between PostgreSQL 9.2 and 9.3.
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> [!NOTE]
> **Fact.** The measured inventory changes from 224 to 231 settings: 9 added, 3 boot-default changes, and 2 removed.

## Added parameters {#added}

| Parameter | Type | Context | Boot default | Category |
| --- | --- | --- | --- | --- |
| [`autovacuum_multixact_freeze_max_age`](/parameters/autovacuum-multixact-freeze-max-age/) | `integer` | `postmaster` | `400000000` | Autovacuum |
| [`data_checksums`](/parameters/data-checksums/) | `bool` | `internal` | `off` | Preset Options |
| [`ignore_checksum_failure`](/parameters/ignore-checksum-failure/) | `bool` | `superuser` | `off` | Developer Options |
| [`lock_timeout`](/parameters/lock-timeout/) | `integer` | `user` | `0 ms` | Client Connection Defaults / Statement Behavior |
| [`unix_socket_directories`](/parameters/unix-socket-directories/) | `string` | `postmaster` | `/var/run/postgresql` | Connections and Authentication / Connection Settings |
| [`vacuum_multixact_freeze_min_age`](/parameters/vacuum-multixact-freeze-min-age/) | `integer` | `user` | `5000000` | Client Connection Defaults / Statement Behavior |
| [`vacuum_multixact_freeze_table_age`](/parameters/vacuum-multixact-freeze-table-age/) | `integer` | `user` | `150000000` | Client Connection Defaults / Statement Behavior |
| [`wal_receiver_timeout`](/parameters/wal-receiver-timeout/) | `integer` | `sighup` | `60000 ms` (1 min) | Replication / Standby Servers |
| [`wal_sender_timeout`](/parameters/wal-sender-timeout/) | `integer` | `sighup` | `60000 ms` (1 min) | Replication / Sending Servers |
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## Boot-default changes {#default-changes}

| Parameter | PG9.2 | PG9.3 | Category |
| --- | --- | --- | --- |
| [`server_version`](/parameters/server-version/) | `9.2.23` | `9.3.25` | Preset Options |
| [`server_version_num`](/parameters/server-version-num/) | `90223` | `90325` | Preset Options |
| [`ssl_ciphers`](/parameters/ssl-ciphers/) | `ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH` | `DEFAULT:!LOW:!EXP:!MD5:@STRENGTH` | Connections and Authentication / Security and Authentication |
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## Removed parameters {#removed}

| Parameter | Last type | Context | Last boot default | Category |
| --- | --- | --- | --- | --- |
| [`replication_timeout`](/parameters/replication-timeout/) | `integer` | `sighup` | `60000 ms` (1 min) | Replication / Sending Servers |
| [`unix_socket_directory`](/parameters/unix-socket-directory/) | `string` | `postmaster` | `""` (empty string) | Connections and Authentication / Connection Settings |
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## Method {#method}

The three lists compare the pinned PG9.2 and PG9.3 `pg_settings` snapshots directly. A default change is a change in the `boot_val` plus `unit` pair; `setting` is excluded so an `initdb`-generated value is not mistaken for the compiled boot default.

- [Machine-readable diff data](/data/diffs.json)
- [Complete GUC JSONL](/data/guc.jsonl)