pgPedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Top / D

• Browse categories
• Random entry
• PostgreSQL releases
  • PostgreSQL 16 (dev)
  • PostgreSQL 15 (latest)
  • PostgreSQL 14
  • PostgreSQL 13
  • PostgreSQL 12
  • PostgreSQL 11
  • PostgreSQL 10 (EOL)

Version charts

SQL commands
System catalog tables
System catalog views
System statistics views
File system functions

Contrib modules
Object Identifier Types
Progress reporting views
Storage parameters (relopts)

Useful overviews

xlog renaming in Pg 10
Online tools for PostgreSQL
Abbreviations and acronyms

Useful links

PostgreSQL documentation
PostgreSQL feature matrix
PostgreSQL versioning policy
PostgreSQL latest versions

@postgrespedia

debug_discard_caches

debug_discard_caches is a configuration parameter instructing PostgreSQL to invalidate each system catalog cache entry at the first possible opportunity.

debug_discard_caches was added in PostgreSQL 14.

Default

The default value for debug_discard_caches is: 0. See the Usage section for exceptions.

Note that debug_discard_caches can only be enabled if PostgreSQL was compiled with the --enable-cassert option, or if DISCARD_CACHES_ENABLED was manually set. Otherwise it is not possible to change the setting.

Usage

debug_discard_caches was introduced to obviate the need to set CLOBBER_CACHE_ALWAYS when building PostgreSQL, and makes it possible to dynamically enable/disable the setting.

For backwards compatibility, debug_discard_caches will be set to 1 if CLOBBER_CACHE_ALWAYS was defined, or 3 if CLOBBER_CACHE_RECURSIVE was defined.

From PostgreSQL 14 the option --clobber-cache can be provided to initdb to bootstrap backends with debug_discard_caches will be set to 1.

Change history

• PostgreSQL 14
  • added (commit 4656e3d6), initially as debug_invalidate_system_caches_always but renamed to debug_discard_caches (commit d68a0039)

References

Categories