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LATERALSQL CommandsPG187.2.1.5. LATERAL Subqueries # Subqueries appearing in FROM can be preceded by the key word LATERAL. This allows them to reference columns provided by preceding FROM items. (Without LATERAL, …Table Expressions › The FROM Clause › LATERAL Subqueries LATERAL SubqueriesManual ChaptersPG187.2.1.5. LATERAL Subqueries Subqueries appearing in FROM can be preceded by the key word LATERAL. This allows them to reference columns provided by preceding FROM items. (Without LATERAL, ea…LATERAL Subqueries latitudeFunctionsPG18latitude ( earth ) → float8 Returns the latitude in degrees of a point on the surface of the Earth.earthdistance — calculate great-circle distances › Cube-Based Earth Distances launchql-base32ExtensionsExtensionsRFC6238 TOTP implementation in pure PostgreSQL plpgsql launchql-base32 SecuritySecurity · Extensions launchql-ext-typesExtensionsExtensions🛠. basic pg utils launchql-ext-types Data typesData types · Extensions launchql-extension-utilsExtensionsExtensionsPostgreSQL utilities launchql-extension-utils UtilitiesUtilities · Extensions launchql-extension-verifyExtensionsExtensionsPostgreSQL verification utilities launchql-extension-verify FeaturesFeatures · Extensions launchql-inflectionExtensionsExtensionsinflection is a port of the functionality from Ruby on Rails' Active Support Inflection classes into PostgreSQL launchql-inflection Functions and aggregatesFunctions and aggregates · Extensions launchql-jwt-claimsExtensionsExtensionslaunchql-jwt-claims extension dependency-closure launchql-jwt-claims source-only sql launchql-jwt-claims SecuritySecurity · Extensions launchql-stampsExtensionsExtensions🛠. basic pg utils launchql-stamps Functions and aggregatesFunctions and aggregates · Extensions launchql-totpExtensionsExtensions🛠. basic pg utils launchql-totp SecuritySecurity · Extensions lc_collateConfigurationReferencelc_collate Preset Options 10 Reports the locale in which sorting of textual data is done. See Section 23.1 for more information. This value is determined when a database is created. 11 12 13…Configuration · Preset Options lc_ctypeConfigurationReferencelc_ctype Preset Options 10 Reports the locale that determines character classifications. See Section 23.1 for more information. This value is determined when a database is created. Ordinaril…Configuration · Preset Options lc_messagesConfigurationReferencelc_messages Client Connection Defaults 10 Sets the language in which messages are displayed. Acceptable values are system-dependent; see Section 23.1 for more information. If this variable i…Configuration · Client Connection Defaults lc_monetaryConfigurationReferencelc_monetary Client Connection Defaults 10 Sets the locale to use for formatting monetary amounts, for example with the to_char family of functions. Acceptable values are system-dependent; se…Configuration · Client Connection Defaults lc_numericConfigurationReferencelc_numeric Client Connection Defaults 10 Sets the locale to use for formatting numbers, for example with the to_char family of functions. Acceptable values are system-dependent; see Section …Configuration · Client Connection Defaults lc_timeConfigurationReferencelc_time Client Connection Defaults 10 Sets the locale to use for formatting dates and times, for example with the to_char family of functions. Acceptable values are system-dependent; see Sec…Configuration · Client Connection Defaults lcaFunctionsPG18lca ( ltree [, ltree [, ... ]] ) → ltree Computes longest common ancestor of paths (up to 8 arguments are supported). lca('1.2.3', '1.2.3.4.5.6') → 1.2ltree — hierarchical tree-like data type › Operators and Functions lcmFunctionsReferencelcm Mathematical Functions And Operators 13 Least common multiple (the smallest strictly positive number that is an integral multiple of both inputs); returns 0 if either input is zero; avai…Functions · Mathematical Functions And Operators LDAP AuthenticationManual ChaptersPG1820.10. LDAP Authentication This authentication method operates similarly to password except that it uses LDAP as the password verification method. LDAP is used only to validate the user name…LDAP Authentication LDAP Lookup of Connection ParametersManual ChaptersPG1832.18. LDAP Lookup of Connection Parameters If libpq has been compiled with LDAP support (option --with-ldap for configure) it is possible to retrieve connection options like host or dbname …LDAP Lookup of Connection Parameters ldap_fdwExtensionsExtensionsForeign data wrapper for querying LDAP servers external-data fdw ldap sql-med ldap_fdw Foreign data wrappersForeign data wrappers · Extensions leadFunctionsReferencelead Window Functions 10 returns value evaluated at the row that is offset rows after the current row within the partition; if there is no such row, instead return default (which must be of …Functions · Window Functions LEASTSQL CommandsPG189.18.4. GREATEST and LEAST # GREATEST(value [, ...]) LEAST(value [, ...]) The GREATEST and LEAST functions select the largest or smallest value from a list of any number of expressions. The …Conditional Expressions › GREATEST and LEAST LEASTFunctionsReferenceLEAST Conditional Expressions 10 The GREATEST and LEAST functions select the largest or smallest value from a list of any number of expressions. The expressions must all be convertible to a …Functions · Conditional Expressions leftFunctionsReferenceleft String Functions And Operators 10 Return first n characters in the string. When n is negative, return all but last |n| characters. left ( str text, n int ) → text Return first n charact…Functions · String Functions And Operators Legal NoticeManual ChaptersPG18Legal Notice PostgreSQL Database Management System (also known as Postgres, formerly known as Postgres95) Portions Copyright © 1996-2026, PostgreSQL Global Development Group Portions Copyrig…Legal Notice lengthFunctionsReferencelength String Functions And Operators 10 Number of characters in string length ( string ) → int Number of characters in string length ( string bytea, encoding name ) → int Number of characte…Functions · String Functions And Operators letterExtensionsExtensionsletter: role-based access control for PostgreSQL letter SecuritySecurity · Extensions level_pivotExtensionsExtensionsLevelDB FDW with support for pivoting and key templating level_pivot Foreign data wrappersForeign data wrappers · Extensions LevenshteinManual ChaptersPG18F.16.3. Levenshtein This function calculates the Levenshtein distance between two strings: levenshtein(source text, target text, ins_cost int, del_cost int, sub_cost int) returns int levensh…Levenshtein Lexical StructureManual ChaptersPG184.1. Lexical Structure SQL input consists of a sequence of commands. A command is composed of a sequence of tokens, terminated by a semicolon (“;”). The end of the input stream also terminat…Lexical Structure lextestExtensionsExtensionsTiny module for PostgreSQL lexer benchmarking benchmarking lexer lextest FeaturesFeatures · Extensions lgammaFunctionsReferencelgamma Mathematical Functions And Operators 18 Natural logarithm of the absolute value of the gamma function lgamma ( double precision ) → double precision Natural logarithm of the absolute …Functions · Mathematical Functions And Operators li3dsExtensionsExtensionsPostgreSQL extension for managing 3D sensor data li3ds GeospatialGeospatial · Extensions libc CollationsManual ChaptersPG1823.2.2.2.1. libc Collations For example, the operating system might provide a locale named de_DE.utf8. initdb would then create a collation named de_DE.utf8 for encoding UTF8 that has both L…libc Collations libc CollationsManual ChaptersPG1823.2.2.3.1. libc Collations New libc collations can be created like this: CREATE COLLATION german (provider = libc, locale = 'de_DE'); The exact values that are acceptable for the locale cla…libc Collations LibpqManual ChaptersPG18E.6.3.5. Libpq Add function PQfullProtocolVersion() to report the full, including minor, protocol version number (Jacob Champion, Jelte Fennema-Nio) § Add libpq connection parameters and env…Libpq libpq — C LibraryManual ChaptersPG18Chapter 32. libpq — C Library libpq is the C application programmer's interface to PostgreSQL. libpq is a set of library functions that allow client programs to pass queries to the PostgreSQ…libpq — C Library LibpqwalreceiverConnectWait EventsReferenceLibpqwalreceiverConnect Client 10 Waiting in WAL receiver to establish connection to remote server. 11 12 13 14 15 16 17 18 19 20 Idle ClientRead sessions are normal connection-pool inventor…Wait Events · Client