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In PostgreSQL 16, the following parameters have been changed. #### 3.3.1 Added parameters {#pg16-3-3-1-added-parameters} The following parameters have been added. [[6e2775e](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=6e2775e4d4e47775f0d933e4a93c148024a3bc63), [e5b8a4c](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=e5b8a4c098ad6add39626a14475148872cd687e0), [1671f99](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=1671f990dd669c0b72e45c7bef0fd579a10676ed), [3226f47](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=3226f47282a05979483475d1e4a11aab8c1bfc39), [5de94a0](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=5de94a041ed7a51b571db2030ba87600c7fc6262), [216a784](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=216a784829c2c5f03ab0c43e009126cbb819e9b2), [b577743](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=b577743000cd0974052af3a71770a23760423102), [51b5834](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=51b5834cd53f0bd068729043b55f7da3ca6bb15f), [1e8b617](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=1e8b61735cfb1a4feb72cb9ea83db690fedbfef1), [3d4fa22](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=3d4fa227bce4294ce1cc214b4a9d3b7caa3f0454), [6de31ce](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=6de31ce446e59a1f947c7ebe4e4bbe7ca2b842bc), [9c0a0e2](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=9c0a0e2ed92a1a94ec30d36f8ea1ab12c928292b)] **Table 23.** Added parameters | 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 |PDF page 72
##### Debug_io_direct {#pg16-p72-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](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=319bae9a8da66678d80d862440e54cebc7b1cc24), [d4e71df](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=d4e71df6d757fd21c363164a3a4d3b5681462662)] **Table 24.** Possible values | 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 {#pg16-p72-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](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=3226f47282a05979483475d1e4a11aab8c1bfc39)] #### 3.3.2 Modified Parameters {#pg16-3-3-2-modified-parameters} The following parameters have been changed in terms of setting range and choices. [[9430fb4](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=9430fb407bb64cc842e56fb5844265a9343dafba), [6c31ac0](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=6c31ac091f31171601ee00972e131d8683e7b828), [5352ca2](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=5352ca22e0012d48055453ca9992a9515d811291), [0981846](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=0981846b9c3ab1dcc351798dcae6a2e35872a6c3)] **Table 25.** Modified Parameters | 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. |PDF page 73
#### 3.3.3 Parameters with default values changed {#pg16-3-3-3-parameters-with-default-values-changed} The following parameters have changed default values. **Table 26.** Parameters with default values changed | Parameter name | PostgreSQL 15 | PostgreSQL 16 | Note | | --- | --- | --- | --- | | server_version | 15.4 | 16.0 | | | server_version_num | 150004 | 160000 | | #### 3.3.4 Removed parameter {#pg16-3-3-4-removed-parameter} The following parameter have been removed. [[b0f6c43](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=b0f6c437160db640d4ea3e49398ebc3ba39d1982), [cd4329d](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=cd4329d9393f84dce34f0bd2dd936adc8ffaa213), [1118cd3](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=1118cd37eb61e6a2428f457a8b2026a7bb3f801a)] **Table 27.** Removed parameters | 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. |