5 Configuration Parameters
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In PostgreSQL 16, the following parameters have been changed.
3.3.1 Added parameters
The following parameters have been added. [6e2775e, e5b8a4c, 1671f99, 3226f47, 5de94a0, 216a784, b577743, 51b5834, 1e8b617, 3d4fa22, 6de31ce, 9c0a0e2]
| Parameter name | Description (context) | Default value |
|---|---|---|
| debug_io_direct | Determine where direct I/O is used (postmaster) | '' |
| debug_logical_replication_streaming | Setting the transfer method for logical replication (user) | buffered |
| createrole_self_grant | Options automatically specified in the GRANT statement (user) | '' |
| enable_presorted_aggregate | Use the sort processing optimization function (user) | on |
| gss_accept_delegation | Whether to accept GSSAPI authentication delegation from the client (sighup) | off |
| icu_validation_level | ICU locale check log output level (user) | error |
| max_parallel_apply_workers_per_subscription | Maximum number of workers per subscription (sighup) | 2 |
| reserved_connections | Number of connections reserved for general users (postmaster) | 0 |
| scram_iterations | SCRAM authentication iteration count (user) | 4096 |
| send_abort_for_crash | Send a SIGABRT signal when the backend crashes (sighup) | off |
| send_abort_for_kill | Send SIGABRT signal when child process is stuck (sighup) | off |
| vacuum_buffer_usage_limit | Default shared buffer size used by VACUUM (user) | 256kB |
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Debug_io_direct
Request the OS to use Direct I/O. Specify O_DIRECT on Linux/UNIX, F_NOCACHE on macOS, and FILE_FLAG_NO_BUFFERING on Windows when opening the file. For the parameter, specify multiple target areas separated by commas (,). [319bae9, d4e71df]
| Value | Description | Note |
|---|---|---|
| data | I/O to main data file | |
| wal | I/O to WAL files | |
| wal_init | I/O for WAL file initialization |
This parameter is currently for developers (Developer Option category).
Send_abort_for_crash / Send_abort_for_kill
The postmaster process first sends a SIGQUIT signal and then a SIGKILL signal when a child process crashes. Send_abort_for_crash and send_abort_for_kill change the signal to SIGABRT by setting each to ‘on’. [3226f47]
3.3.2 Modified Parameters
The following parameters have been changed in terms of setting range and choices. [9430fb4, 6c31ac0, 5352ca2, 0981846]
| Parameter name | Changes |
|---|---|
| archive_command | It can no longer be set at the same time as archive_library. |
| archive_library | It can no longer be set at the same time as archive_command. |
| wal_sync_method | It is now possible to specify fdatasync on NTFS in Windows environment. |
| shared_preload_libraries | Now also handled in single user mode (backported to PostgreSQL 15). |
| debug_parallel_query | Renamed from force_parallel_mode. |
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3.3.3 Parameters with default values changed
The following parameters have changed default values.
| Parameter name | PostgreSQL 15 | PostgreSQL 16 | Note |
|---|---|---|---|
| server_version | 15.4 | 16.0 | |
| server_version_num | 150004 | 160000 |
3.3.4 Removed parameter
The following parameter have been removed. [b0f6c43, cd4329d, 1118cd3]
| Parameter name | Reason |
|---|---|
| lc_collate | This was determined to be unnecessary, because the exact perdatabase value must be referenced in the pg_database view. |
| lc_ctype | This was determined to be unnecessary, because the exact perdatabase value must be referenced in the pg_database view. |
| promote_trigger_file | Removed because process startup every 5 seconds was deemed useless and trigger files are no longer supported. |
| vacuum_defer_cleanup_age | Removed due to difficulty in determining a reasonable setpoint and the availability of alternatives. |