Appendix F. Additional Supplied Modules and Extensions

Table of Contents

F.1. adminpack — pgAdmin support toolpack
F.2. amcheck — tools to verify table and index consistency
F.3. aqo — cost-based query optimization
F.4. auth_delay — pause on authentication failure
F.5. auto_explain — log execution plans of slow queries
F.6. basebackup_to_shell — example "shell" pg_basebackup module
F.7. basic_archive — an example WAL archive module
F.8. bloom — bloom filter index access method
F.9. btree_gin — GIN operator classes with B-tree behavior
F.10. btree_gist — GiST operator classes with B-tree behavior
F.11. citext — a case-insensitive character string type
F.12. cube — a multi-dimensional cube data type
F.13. dblink — connect to other Postgres Pro databases
F.14. dict_int — example full-text search dictionary for integers
F.15. dict_xsyn — example synonym full-text search dictionary
F.16. dump_stat — functions to backup and recover the pg_statistic table
F.17. earthdistance — calculate great-circle distances
F.18. fasttrun — a transaction unsafe function to truncate temporary tables
F.19. file_fdw — access data files in the server's file system
F.20. fulleq — an additional equivalence operator for compatibility with Microsoft SQL Server
F.21. fuzzystrmatch — determine string similarities and distance
F.22. hstore — hstore key/value datatype
F.23. Hunspell Dictionaries Modules
F.24. intagg — integer aggregator and enumerator
F.25. intarray — manipulate arrays of integers
F.26. isn — data types for international standard numbers (ISBN, EAN, UPC, etc.)
F.27. jsquery — a language to query jsonb data type
F.28. lo — manage large objects
F.29. ltree — hierarchical tree-like data type
F.30. mchar — additional data types for compatibility with Microsoft SQL Server
F.31. online_analyze — update statistics after INSERT, UPDATE, DELETE, or SELECT INTO operations
F.32. old_snapshot — inspect old_snapshot_threshold state
F.33. pageinspect — low-level inspection of database pages
F.34. passwordcheck — verify password strength
F.35. pg_buffercache — inspect Postgres Pro buffer cache state
F.36. pgcrypto — cryptographic functions
F.37. pg_freespacemap — examine the free space map
F.38. pg_pathman — an optimized partitioning solution for large and distributed databases
F.39. pg_proaudit — enables detailed logging of various security events
F.40. pgpro_pwr — workload reports
F.41. pg_prewarm — preload relation data into buffer caches
F.42. pgpro_stats — a means for tracking planning and execution statistics of all SQL statements executed by a server
F.43. pg_query_state — a facility to know the current state of query execution on working backend
F.44. pgrowlocks — show a table's row locking information
F.45. pg_stat_statements — track statistics of SQL planning and execution
F.46. pgstattuple — obtain tuple-level statistics
F.47. pg_surgery — perform low-level surgery on relation data
F.48. pg_trgm — support for similarity of text using trigram matching
F.49. pg_tsparser — an extension for text search
F.50. pg_variables — functions for working with variables of various types
F.51. pg_visibility — visibility map information and utilities
F.52. pg_wait_sampling — collecting sampling-based statistics on wait events
F.53. pg_walinspect — low-level WAL inspection
F.54. plantuner — hints for the planner to disable or enable indexes for query execution
F.55. postgres_fdw — access data stored in external Postgres Pro servers
F.56. ptrack — a block-level incremental backup engine for Postgres Pro
F.57. rum — an access method to work with the RUM indexes
F.58. seg — a datatype for line segments or floating point intervals
F.59. sepgsql — SELinux-, label-based mandatory access control (MAC) security module
F.60. shared_ispell — a shared ispell dictionary
F.61. spi — Server Programming Interface features/examples
F.62. sslinfo — obtain client SSL information
F.63. tablefunc — functions that return tables (crosstab and others)
F.64. tcn — a trigger function to notify listeners of changes to table content
F.65. test_decoding — SQL-based test/example module for WAL logical decoding
F.66. tsm_system_rows — the SYSTEM_ROWS sampling method for TABLESAMPLE
F.67. tsm_system_time — the SYSTEM_TIME sampling method for TABLESAMPLE
F.68. unaccent — a text search dictionary which removes diacritics
F.69. uuid-ossp — a UUID generator
F.70. xml2 — XPath querying and XSLT functionality

This appendix and the next one contain information on the optional components available in the Postgres Pro Standard distribution. These include porting tools, analysis utilities, and plug-in features that are not part of the core Postgres Pro system. They are separate mainly because they address a limited audience or are too experimental to be part of the main source tree. This does not preclude their usefulness.

This appendix covers the extensions and other server plug-in modules. Appendix G covers the utility programs.

In Postgres Pro Standard, these modules are made available as a separate subpackage postgrespro-std-16-contrib.

Many components supply new user-defined functions, operators, or types, packaged as extensions. To make use of one of these extensions, after you have installed the code you need to register the new SQL objects in the database system. This is done by executing a CREATE EXTENSION command. In a fresh database, you can simply do

CREATE EXTENSION extension_name;

This command registers the new SQL objects in the current database only, so you need to run it in every database in which you want the extension's facilities to be available. Alternatively, run it in database template1 so that the extension will be copied into subsequently-created databases by default.

For all extensions, the CREATE EXTENSION command must be run by a database superuser, unless the extension is considered trusted. Trusted extensions can be run by any user who has CREATE privilege on the current database. Extensions that are trusted are identified as such in the sections that follow. Generally, trusted extensions are ones that cannot provide access to outside-the-database functionality.

The following extensions are trusted in a default installation:

btree_ginfuzzystrmatchltreetcn
btree_gisthstorepgcryptotsm_system_rows
citextintarraypg_trgmtsm_system_time
cubeisnsegunaccent
dict_intlotablefuncuuid-ossp

Many extensions allow you to install their objects in a schema of your choice. To do that, add SCHEMA schema_name to the CREATE EXTENSION command. By default, the objects will be placed in your current creation target schema, which in turn defaults to public.

Note, however, that some of these components are not extensions in this sense, but are loaded into the server in some other way, for instance by way of shared_preload_libraries. See the documentation of each component for details.