A.1. Release 4.6.0

A.1.1. Overview

This release adds convenient features for logging and administration of Pgpool-II. Now you can rotate log without restarting or sending a signal to Pgpool-II by using new PCP command. logging_collector related parameters can be changed by reloading of the configuration file. Also new PC commands are added to invalidate query cache without restarting Pgpool-II. Another features for query cache are forcing to create a query cache entry and removing particular query cache entry. New configuration parameter log_backend_messages allows to log messages from backend for easier analysis of communication between Pgpool-II and PostgreSQL. The SQL parser is updated to sync with the latest PostgreSQL 17 version as usual. Finally now you can use IPv6 for watchdog's hostname and heartbeat_hostname parameter.

Major enhancements are as follows:

• New PCP command to trigger log rotation.

• Allow logging_collector related parameters to be changed by reloading.

• New PCP command to invalidate query cache.

• Allow to force to create query cache

• New PGPOOL SET CACHE DELETE command.

• New configuration parameter log_backend_messages.

• Import PostgreSQL 17's SQL parser.

• Add IPv6 support for watchdog hostname and heartbeat_hostname parameter.

A.1.2. Migration to Version 4.6

• The default values of health_check_user, recovery_user, sr_check_user and wd_lifecheck_user are changed from 'noboy' to '' (empty string). You need to set them in 4.6. Otherwise you will get an error.

• Ignore leading/trailing spaces in string list type configuration parameters, for example, unix_socket_directories and pcp_socket_dir.

• The following log messages appear when a child process exits due to child_life_time or child_max_connections. Downgrade them to DEBUG1 because they are normal messages.

    reaper handler
    reaper handler: exiting normally
       

A.1.3. Changes

• Add pcp_log_rotate to trigger log rotation. (Bo Peng)

• Allow logging_collector related parameters to be changed by reloading the Pgpool-II configurations. (Bo Peng)

  The following logging_collector related parameters can now be changed by reloading:

  • log_truncate_on_rotation

  • log_directory

  • log_filename

  • log_rotation_age

  • log_rotation_size

  • log_file_mode

• Add pcp_invalidate_query_cache to invalidate query cache. (Tatsuo Ishii)

• Add PGPOOL SET CACHE DELETE command to invalidate specified query cache entry. (Tatsuo Ishii)

• Add new configuration parameter log_backend_messages to log protocol messages from each backend. (Tatsuo Ishii)

• Import PostgreSQL 17 RC1 new parser. (Bo Peng)

  Major changes of PostgreSQL 17 parser include:

  - Allow MERGE to use NOT MATCHED BY SOURCE and RETURNING clause:
  
      MERGE INTO ... WHEN NOT MATCHED BY SOURCE ...
      MERGE INTO ... RETURNING ...
  
  - Add new COPY option ON_ERROR ignore and LOG_VERBOSITY:
  
    COPY ... WITH (ON_ERROR ignore);
    COPY ... WITH (LOG_VERBOSITY verbose);
  
  - Allow to use '*' to specify the COPY FROM options FORCE_NOT_NULL and FORCE_NULL for all columns.
  
    COPY ... WITH (FORCE_NOT_NULL *);
    COPY ... WITH (FORCE_NULL *);
  
  - Add EXPLAIN option SERIALIZE and MEMORY
  
    EXPLAIN (MEMORY) ...
    EXPLAIN (ANALYZE, SERIALIZE ...) ...
  
  - Allow ALTER TABLE to use SET STATISTICS DEFAULT to set a column to the default statistics target
  
    ALTER TABLE ... ALTER COLUMN ... SET STATISTICS DEFAULT;
  
  - Allow ALTER TABLE to change a column's generation expression
  
    ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION;
  
  - Add DEFAULT setting for ALTER TABLE .. SET ACCESS METHOD
  
    ALTER TABLE ... SET ACCESS METHOD new_access_method DEFAULT;
  
  - Allow event triggers to use login event:
  
    CREATE EVENT TRIGGER ... ON login ...
  
  - Add event trigger support for REINDEX.
       

• Add IPv6 support for hostname and heartbeat_hostname parameter. (Kwangwon Seo)

• Ignore leading/trailing spaces in string list type configuration parameters. (Bo Peng)

  If the string list type configuration parameters (e.g. unix_socket_directories, pcp_socket_dir, etc.) contain white spaces, it may cause startup failure.

• Downgrade reaper handler logs. (Bo Peng)

  The following log messages appear when a child process exits due to settings (e.g., child_life_time or child_max_connections) . Downgrade them to DEBUG1 because they are normal messages.

    reaper handler
    reaper handler: exiting normally
       

• Eliminate unnecessary memory allocation in extended query protocol. (Tatsuo Ishii) Note this is only releated to streaming replication mode.

A.1.4. Bug fixes

• This release fixes the same bugs as other minor releases. See Appendix A for more details of those fixes.