Supported database extensions

This page lists the PostgreSQL extensions that AlloyDB supports. Extensions not listed below are not supported.

In general, you enable an extension by connecting to a database in an AlloyDB cluster's primary instance and entering a LOAD or CREATE EXTENSION command. Here is an example that uses psql to connect to the mydatabase database as the postgres user and enable the citext extension:

psql -h PRIMARY_INSTANCE_IP_ADDRESS -d mydatabase -U postgres

mydatabase=> CREATE EXTENSION IF NOT EXISTS citext;

Some extensions require you to set one or more database flags before you can use the LOAD or CREATE EXTENSION command to enable the extension. You enable flags on the AlloyDB primary instance or read pool instance where you want to use the extension. In the table below, extensions that have this requirement state which database flags you must set.

Extension Description
auto_explain Enables automatic logging of execution plans of slow statements, for troubleshooting and more. It provides an automated way to perform the functionality of the EXPLAIN command.
bloom Provides an index access method based on Bloom filters.
btree_gin Provides sample GIN operator classes that implement B-tree equivalent behavior.
btree_gist Provides GiST index operator classes that implement B-tree equivalent behavior.
citext Provides a case-insensitive character string type citext.
cube Implements a data type cube for representing multidimensional cubes.
dblink Provides functions to connect to PostgreSQL databases from within a database session.
dict_int An add-on dictionary template for full-text search that controls the indexing of integers.
earthdistance Provides two approaches to calculating great circle distances on the surface of the Earth.
fuzzystrmatch Provides several functions to determine similarities and distance between strings.
google_columnar_engine Provides the columnar engine feature of AlloyDB, which handles HTAP (hybrid transactional analytical processing) and OLAP (online analytical processing) workloads very efficiently.
google_db_advisor Provides the index advisor feature of AlloyDB, which recommends indexes to speed up query processing.
google_ml_integration Provides functions you use to access Vertex AI prediction endpoints to get predictions in SQL.
hll (postgresql-hll) Introduces a new data type, hll, which is a HyperLogLog data structure.
hstore Implements the hstore data type for storing sets of key/value pairs within a single PostgreSQL value.
hypopg Provides support for hypothetical indexes.
intagg Provides an integer aggregator and an enumerator.
intarray Provides a set of functions and operators for manipulating null-free arrays of integers and performing indexed searches on them.
ip4r Provides data types for IPv4/v6 addresses, and address ranges, plus index support.
isn Provides data types for some international product numbering standards.
lo Support for managing Large Objects (also called LOs or BLOBs).
ltree Implements a data type ltree for representing labels of data stored in a hierarchical tree-like structure.
pageinspect Inspects the contents of database pages at a low level.
pg_bigm Provides full text search capability in PostgreSQL using 2-gram (bigram) indexes for faster full text searches.
pg_buffercache Provides a means for examining what's happening in the shared buffer cache in real time.
pg_cron Provides is a simple cron-based job scheduler for PostgreSQL that runs inside the database as an extension. It uses the same syntax as regular cron, but it allows you to schedule PostgreSQL commands directly from the database.
pg_freespacemap Examines the free space map (FSM).
pg_hint_plan Enables you to improve PostgreSQL execution plans using hints, which are simple descriptions in SQL comments.
pg_partman Enables you to create and manage time-based and serial-based table partition sets.
pg_prewarm Provides a convenient way to load relation data into either the operating system buffer cache or the PostgreSQL buffer cache.
pg_proctab Enables you to use pg_top with AlloyDB, and generate reports from the operating system process table.
pg_repack Lets you remove bloat from tables and indexes. Optionally, lets you perform an online CLUSTER (order tables by cluster index).
pg_similarity Provides support for similarity queries on PostgreSQL.
pg_stat_statements Provides a means for tracking execution statistics of all SQL statements executed.
pg_trgm Provides functions and operators for determining the similarity of alphanumeric text based on trigram matching, as well as index operator classes that support fast searching for similar strings.
pg_visibility Provides a way to examine the visibility map (VM) and the page-level visibility information of a table.
pg_wait_sampling Provides the ability to collect sampling statistics of wait events.
pgaudit Provides detailed session and object audit logging using the standard logging facility provided by PostgreSQL.
pgcrypto Provides cryptographic functions for PostgreSQL.
pgfincore A set of functions to manage pages in operating system disk cache memory from PostgreSQL.
pglogical Provides logical streaming replication for PostgreSQL using a publish/subscribe model.
pgrowlocks Provides row locking information for the specified table.
pgstattuple Provides various functions to obtain tuple-level statistics.
pgtap Provides a unit testing framework for PostgreSQL, written in PL/pgSQL and PL/SQL.
plpgsql A loadable procedural language for creating functions, procedures and triggers. You also can use this language for direct execution of code in DO blocks.
plproxy Procedural language handler that allows remote procedure calls among PostgreSQL databases, with optional sharding.
PostGIS:
postgis, postgis_raster, postgis_sfcgal postgis_tiger_geocoder, postgis_topology, address_standardizer, address_standardizer_data_us
Provides a spatial database extender for PostgreSQL. It adds support for geographic objects and allows location queries to be run in SQL.
postgres_fdw Provides a foreign-data wrapper that you can use to access data stored in external PostgreSQL servers.
prefix Provides prefix-matching, plus index support.
sslinfo Provides information about the SSL certificate that the current client provided when it connected to the instance.
tablefunc Provides various functions that return tables (multiple rows).
tsm_system_rows Provides the table sampling method SYSTEM_ROWS, which can be used in the TABLESAMPLE clause of a SELECT command.
tsm_system_time Provides the table sampling method SYSTEM_TIME, which can be used in the TABLESAMPLE clause of a SELECT command.
unaccent A text search dictionary that removes accents (diacritic signs) from lexemes.
uuid-ossp Provides functions to generate universally unique identifiers (UUIDs) using one of several standard algorithms.