Search PostgreSQL documentation

^FunctionsPG18numeric ^ numeric → numeric double precision ^ double precision → double precision Exponentiation 2 ^ 3 → 8 Unlike typical mathematical practice, multiple uses of ^ will associate left to ri…Mathematical Functions and Operators ^@FunctionsPG18text ^@ text → boolean Returns true if the first string starts with the second string (equivalent to the starts_with() function). 'alphabet' ^@ 'alph' → tString Functions and Operators A Brief History of PostgreSQLManual ChaptersPG182. A Brief History of PostgreSQL The object-relational database management system now known as PostgreSQL is derived from the POSTGRES package written at the University of California at Berk…A Brief History of PostgreSQL A Complete Event Trigger ExampleManual ChaptersPG1838.3. A Complete Event Trigger Example Here is a very simple example of an event trigger function written in C. (Examples of triggers written in procedural languages can be found in the docu…A Complete Event Trigger Example A Complete Trigger ExampleManual ChaptersPG1837.4. A Complete Trigger Example Here is a very simple example of a trigger function written in C. (Examples of triggers written in procedural languages can be found in the documentation of …A Complete Trigger Example A Database Login Event Trigger ExampleManual ChaptersPG1838.5. A Database Login Event Trigger Example The event trigger on the login event can be useful for logging user logins, for verifying the connection and assigning roles according to current…A Database Login Event Trigger Example A First Rule Step by StepManual ChaptersPG1839.4.1.1. A First Rule Step by Step Say we want to trace changes to the sl_avail column in the shoelace_data relation. So we set up a log table and a rule that conditionally writes a log ent…A First Rule Step by Step A Sample Application Using SQLDAManual ChaptersPG1834.7.2.4. A Sample Application Using SQLDA Here is an example program, which describes how to fetch access statistics of the databases, specified by the input parameters, from the system cat…A Sample Application Using SQLDA A Table Rewrite Event Trigger ExampleManual ChaptersPG1838.4. A Table Rewrite Event Trigger Example Thanks to the table_rewrite event, it is possible to implement a table rewriting policy only allowing the rewrite in maintenance windows. Here's a…A Table Rewrite Event Trigger Example a5pgExtensionsExtensionsEqual-area A5 spatial index functions for PostgreSQL. pgrx a5pg GeospatialGeospatial · Extensions abbrevFunctionsReferenceabbrev Network Address Functions And Operators 10 abbreviated display format as text abbrev ( inet ) → text abbreviated display format as text abbrev ( cidr ) → text abbreviated display form…Functions · Network Address Functions And Operators ABI CompatibilityManual ChaptersPG1836.10.6.3. ABI Compatibility The ABI, or application binary interface, is the interface used at run time.ABI Compatibility ABORTManual ChaptersPG18ABORT ABORT — abort the current transaction Synopsis ABORT [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ]ABORT ABORTSQL CommandsReferenceABORT Transactions 10 abort the current transaction ABORT [ WORK | TRANSACTION ] ABORT rolls back the current transaction and causes all the updates made by the transaction to be discarded. …SQL Commands · Transactions absFunctionsReferenceabs Mathematical Functions And Operators 10 absolute value abs ( x ) → (same as input) absolute value 11 12 13 Absolute value abs ( numeric_type ) → numeric_type Absolute value 14 15 16 17 1…Functions · Mathematical Functions And Operators acExtensionsExtensionsAccess Control Postgres extension (with dev environment) ac SecuritySecurity · Extensions accel_extExtensionsExtensionsFine-grained accelerator offload runtime that overlaps GPU, HSM, or inference work with other PostgreSQL requests. accelerator-offload concurrency coroutines cuda fibers gpu-computing high-p…Features · Extensions Access Privilege Inquiry FunctionsManual ChaptersPG189.27.2. Access Privilege Inquiry Functions Table 9.72 lists functions that allow querying object access privileges programmatically. (See Section 5.8 for more information about privileges.) …Access Privilege Inquiry Functions Accessing a DatabaseManual ChaptersPG181.4. Accessing a Database Once you have created a database, you can access it by: Running the PostgreSQL interactive terminal program, called psql, which allows you to interactively enter, e…Accessing a Database Accessing ArraysManual ChaptersPG188.15.3. Accessing Arrays Now, we can run some queries on the table. First, we show how to access a single element of an array. This query retrieves the names of the employees whose pay chang…Accessing Arrays Accessing Composite TypesManual ChaptersPG188.16.3. Accessing Composite Types To access a field of a composite column, one writes a dot and the field name, much like selecting a field from a table name. In fact, it's so much like sele…Accessing Composite Types Accessing Special Data TypesManual ChaptersPG1834.4.4.2. Accessing Special Data Types ECPG contains some special types that help you to interact easily with some special data types from the PostgreSQL server. In particular, it has implem…Accessing Special Data Types Accessing XML ValuesManual ChaptersPG188.13.3. Accessing XML Values The xml data type is unusual in that it does not provide any comparison operators. This is because there is no well-defined and universally useful comparison alg…Accessing XML Values accountExtensionsExtensionsAdd team, billing, and permission support to Supabase. dbdev supabase tle account FeaturesFeatures · Extensions accumulo_access_pgExtensionsExtensionsPostgreSQL extension for parsing and evaluating Accumulo Access Expressions. pgrx accumulo_access_pg SecuritySecurity · Extensions acdatExtensionsExtensionsCompiled Aho-Corasick double-array machines for exact multi-pattern matching and replacement in PostgreSQL. aho-corasick multi-pattern dictionary text-search bytea redaction acdat Full-text …Full-text search · Extensions AcknowledgmentsManual ChaptersPG18E.6.4. Acknowledgments The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues. Abhishek C…Acknowledgments aclExtensionsExtensionsACL Data type pg_acl Data typesData types · Extensions acldefaultFunctionsReferenceacldefault System Information Functions And Operators 12 get the default access privileges for an object belonging to ownerId acldefault ( type, ownerId ) → aclitem[] get the default access …Functions · System Information Functions And Operators aclexplodeFunctionsReferenceaclexplode System Information Functions And Operators 12 get aclitem array as tuples aclexplode ( aclitem[] ) → setof record get aclitem array as tuples 13 Returns the aclitem array as a set…Functions · System Information Functions And Operators aclexplodeExtensionsExtensionsA backport of aclexplode function for PostgreSQL 8.4 and below acl administration backport aclexplode SecuritySecurity · Extensions acosFunctionsReferenceacos Mathematical Functions And Operators 10 inverse cosine acos ( x ) inverse cosine 11 12 13 Inverse cosine, result in radians acos ( double precision ) → double precision Inverse cosine, …Functions · Mathematical Functions And Operators acosdFunctionsReferenceacosd Mathematical Functions And Operators 10 inverse cosine acosd ( x ) inverse cosine 11 12 13 Inverse cosine, result in degrees acosd ( double precision ) → double precision Inverse cosin…Functions · Mathematical Functions And Operators acoshFunctionsReferenceacosh Mathematical Functions And Operators 12 inverse hyperbolic cosine acosh ( x ) inverse hyperbolic cosine 13 Inverse hyperbolic cosine acosh ( double precision ) → double precision Inver…Functions · Mathematical Functions And Operators acoustidExtensionsExtensionsPostgreSQL extension for working with AcoustID fingerprints acoustid audio-fingerprinting postgresql postgresql-extension acoustid Functions and aggregatesFunctions and aggregates · Extensions AcronymsManual ChaptersPG18Appendix L. Acronyms This is a list of acronyms commonly used in the PostgreSQL documentation and in discussions about PostgreSQL. AIO Asynchronous I/O ACL Access Control List AM Access Meth…Acronyms adaptive_counterExtensionsExtensionsAggregation functions and data type for distinct estimation based on adaptive sampling. adaptive aggregate count distinct estimate sampling wegman distinct_estimators Functions and aggregate…Functions and aggregates · Extensions Adding a ColumnManual ChaptersPG185.7.1. Adding a Column To add a column, use a command like: ALTER TABLE products ADD COLUMN description text; The new column is initially filled with whatever default value is given (null if…Adding a Column Adding a ConstraintManual ChaptersPG185.7.3. Adding a Constraint To add a constraint, the table constraint syntax is used. For example: ALTER TABLE products ADD CHECK (name <> ''); ALTER TABLE products ADD CONSTRAINT some_name U…Adding a Constraint AddinShmemInitWait EventsReferenceAddinShmemInit LWLock 10 Waiting to manage space allocation in shared memory. 11 12 13 Waiting to manage an extension's space allocation in shared memory. 14 15 16 17 18 19 20 9.6 A brief sa…Wait Events · LWLock