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The following parameters have been changed in PostgreSQL 9.5. #### 3.3.1 Added Parameters {#pg9-5-3-3-1-added-parameters} The following parameters have been added. **Table 20.** Added Parameters | Parameter Name | Description | Default Value | | --- | --- | --- | | cluster_name | The name that is included in process titles | '' | | gin_pending_list_limit | Maximum size of the GIN pending list | 4MB | | row_security | Enable Row Level Security feature. available value: on, off and force | on | | track_commit_timestamp | Output the last commit time of the transaction to WAL | off | | wal_compression | WAL compression at the full page write | off | | log_replication_commands | Output log about replication command | off | | max_wal_size | WAL size to start the checkpoint; the range of values: 2 - 2147483647 | 1GB | | min_wal_size | WAL size to start the recycling the WAL files; the range of values: 2 - 2147483647 | 80MB | | operator_precedence_warning | Output a warning to the SQL that has a possibility of changing that the result due to the change in priorities | off | | wal_retrieve_retry_interval | The re-acquisition interval of the WAL data in milliseconds | 5s | ##### wal_retrieve_retry_interval parameter {#pg9-5-p27-wal-retrieve-retry-interval-parameter} Wal_retrieve_retry_interval has been parameterized from the fixed value setting in the previous version. The default value of 5 seconds is the same behavior as the previous version. #### 3.3.2 Changed Parameters {#pg9-5-3-3-2-changed-parameters} The following parameters are changed in the range of setting or the options.PDF page 28
**Table 21.** Changed Parameters | Parameter Name | Modification | | --- | --- | | log_autovacuum_min_duration | Can be specified for each table | | archive_mode | "always" can be specified | | trace_sort | The output of the additional information | | debug_assertions | Became read-only | | local_preload_libraries | Allow set by ALTER ROLE SET statement | ##### log_autovacuum_min_duration {#pg9-5-p28-log-autovacuum-min-duration} Parameter log_autovacuum_min_duration can now be specified for each table. **Example 16.** Setting parameter for each table ```text postgres=> ALTER TABLE vacuum1 SET (log_autovacuum_min_duration = 1000) ; ALTER TABLE postgres=> \d+ vacuum1 Table "public.vacuum1" Column | Type | Modifiers | Storage | Stats target | Description --------+-----------------------+-----------+----------+--------------+-------- c1 | numeric | | main | | c2 | character varying(10) | | extended | | Options: log_autovacuum_min_duration=1000 ``` ##### archive_mode {#pg9-5-p28-archive-mode} "always" has been added to the choice of the parameter archive_mode. There is no difference between "on" and "always" except the slave instance in the replication environment. If this parameter is specified to "always" in the slave instance, archiver process is started, and the archive log is output.PDF page 29
#### 3.3.3 Parameters changed the default value {#pg9-5-3-3-3-parameters-changed-the-default-value} The default values of the following parameters have been changed. **Table 22.** Parameters the default value of which is changed | Parameter Name | PostgreSQL 9.4 | PostgreSQL 9.5 | | --- | --- | --- | | server_version 9.4.4 | server_version 9.4.4 | 9.5alpha2 | | server_version_num 90404 | server_version_num 90404 | 90500 | | search_path | "$user",public | "$user", public | #### 3.3.4 Obsoleted Parameter {#pg9-5-3-3-4-obsoleted-parameter} The following parameters are obsoleted. ##### Obsoleted checkpoint_segments {#pg9-5-p29-obsoleted-checkpoint-segments} Parameter checkpoint_segments, which determine the occurrence time of the checkpoint, is obsolete and has been divided into parameter max_wal_size and min_wal_size. **Table 23.** Alternative parameters for checkpoint\_segments | Parameter Name | Description | Default Value | | --- | --- | --- | | max_wal_size | Maximum size to let the WAL grow to between automatic WAL checkpoints. | 1GB | | min_wal_size | As long as WAL disk usage stays below this setting. | 80MB | In previous version, parameters checkpoint_segments, was used for both starting the checkpoint and recycling the WAL file. Therefore, when the interval of the checkpoint was extended, a lot of WAL file was created. This feature has been changed so as to control the two functions by separate parameters in the PostgreSQL 9.5. ##### Obsoleted ssl_renegotiation_limit {#pg9-5-p29-obsoleted-ssl-renegotiation-limit} Parameter ssl_renegotiation_limit is obsoleted. #### 3.3.5 Changed parameters in recovery.conf File {#pg9-5-3-3-5-changed-parameters-in-recovery-conf-file} The following parameters of the recovery.conf file has been changed.PDF page 30
##### Added recovery_target_action parameter {#pg9-5-p30-added-recovery-target-action-parameter} Parameter recovery_target_action has been added. This parameter has extended the pause_at_recovery_target parameter of the previous version more generally. The operation in case it reaches the recovery target can be specified. You can specify the following values. ##### pause (default value) {#pg9-5-p30-pause-default-value} Wait in a state where instance has reached the target. ##### promote {#pg9-5-p30-promote} Complete the recovery, and accept the user's connection. ##### shutdown {#pg9-5-p30-shutdown} Complete the recovery, and stop the instance. Renaming recovery.conf file will not be performed. ##### Obsoleted parameter {#pg9-5-p30-obsoleted-parameter} Parameter pause_at_recovery_target has been removed. As an alternative parameter, abovementioned recovery_target_action is used. When the parameter pause_at_recovery_target is specified in recovery.conf file, the following message is logged and instance cannot be started. **Example 17.** Error by pause\_at\_recovery\_target setting ```bash $ cat data/recovery.conf restore_command = 'cp /usr/local/pgsql/arch/%f %p' pause_at_recovery_target = on $ $ pg_ctl -D data -w start waiting for server to start....LOG: redirecting log output to logging collector process HINT: Future log output will appear in directory "pg_log". .... stopped waiting pg_ctl: could not start server Examine the log output $ $ cat data/pg_log/postgresql-2015-08-07_111751.log LOG: database system was shut down at 2015-08-07 11:17:20 JST FATAL: unrecognized recovery parameter "pause_at_recovery_target" LOG: startup process (PID 12233) exited with exit code 1 LOG: aborting startup due to startup process failure ```