# PostgreSQL 9.4 → 9.5 GUC diff

> Core configuration parameters added, removed, or changed in boot default between PostgreSQL 9.4 and 9.5.
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> [!NOTE]
> **Fact.** The measured inventory changes from 240 to 249 settings: 11 added, 3 boot-default changes, and 2 removed.

## Added parameters {#added}

| Parameter | Type | Context | Boot default | Category |
| --- | --- | --- | --- | --- |
| [`cluster_name`](/parameters/cluster-name/) | `string` | `postmaster` | `""` (empty string) | Process Title |
| [`extension_destdir`](/parameters/extension-destdir/) | `string` | `superuser` | `""` (empty string) | File Locations |
| [`gin_pending_list_limit`](/parameters/gin-pending-list-limit/) | `integer` | `user` | `4096 kB` (4 MiB) | Client Connection Defaults / Statement Behavior |
| [`log_replication_commands`](/parameters/log-replication-commands/) | `bool` | `superuser` | `off` | Reporting and Logging / What to Log |
| [`max_wal_size`](/parameters/max-wal-size/) | `integer` | `sighup` | `64 16MB` (1 GiB (64 × 16MB)) | Write-Ahead Log / Checkpoints |
| [`min_wal_size`](/parameters/min-wal-size/) | `integer` | `sighup` | `5 16MB` (80 MiB (5 × 16MB)) | Write-Ahead Log / Checkpoints |
| [`operator_precedence_warning`](/parameters/operator-precedence-warning/) | `bool` | `user` | `off` | Version and Platform Compatibility / Previous PostgreSQL Versions |
| [`row_security`](/parameters/row-security/) | `bool` | `user` | `on` | Connections and Authentication / Security and Authentication |
| [`track_commit_timestamp`](/parameters/track-commit-timestamp/) | `bool` | `postmaster` | `off` | Replication |
| [`wal_compression`](/parameters/wal-compression/) | `bool` | `superuser` | `off` | Write-Ahead Log / Settings |
| [`wal_retrieve_retry_interval`](/parameters/wal-retrieve-retry-interval/) | `integer` | `sighup` | `5000 ms` (5 s) | Replication / Standby Servers |
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## Boot-default changes {#default-changes}

| Parameter | PG9.4 | PG9.5 | Category |
| --- | --- | --- | --- |
| [`search_path`](/parameters/search-path/) | `"$user",public` | `"$user", public` | Client Connection Defaults / Statement Behavior |
| [`server_version`](/parameters/server-version/) | `9.4.26` | `9.5.25` | Preset Options |
| [`server_version_num`](/parameters/server-version-num/) | `90426` | `90525` | Preset Options |
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## Removed parameters {#removed}

| Parameter | Last type | Context | Last boot default | Category |
| --- | --- | --- | --- | --- |
| [`checkpoint_segments`](/parameters/checkpoint-segments/) | `integer` | `sighup` | `3` | Write-Ahead Log / Checkpoints |
| [`ssl_renegotiation_limit`](/parameters/ssl-renegotiation-limit/) | `integer` | `user` | `0 kB` (0 B) | Connections and Authentication / Security and Authentication |
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## Method {#method}

The three lists compare the pinned PG9.4 and PG9.5 `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)