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clusterdbCommand-line ToolsPG18clusterdb clusterdb — cluster a PostgreSQL database Synopsis clusterdb [connection-option...] [option...] [ --table | -t table ] ... [ dbname | -a | --all ]clusterdb clusterdbManual ChaptersPG18clusterdb clusterdb — cluster a PostgreSQL database Synopsis clusterdb [connection-option...] [option...] [ --table | -t table ] ... [ dbname | -a | --all ]clusterdb clusterdb --allCommand-line ToolsPG18-a--all Cluster all databases.clusterdb › Options clusterdb --echoCommand-line ToolsPG18-e--echo Echo the commands that clusterdb generates and sends to the server.clusterdb › Options clusterdb --helpCommand-line ToolsPG18-?--help Show help about clusterdb command line arguments, and exit.clusterdb › Options clusterdb --host=hostCommand-line ToolsPG18-h host--host=host Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix domain socket.clusterdb › Options clusterdb --maintenance-db=dbnameCommand-line ToolsPG18--maintenance-db=dbname When the -a/--all is used, connect to this database to gather the list of databases to cluster. If not specified, the postgres database will be used, or if that does …clusterdb › Options clusterdb --no-passwordCommand-line ToolsPG18-w--no-password Never issue a password prompt. If the server requires password authentication and a password is not available by other means such as a .pgpass file, the connection attempt wi…clusterdb › Options clusterdb --passwordCommand-line ToolsPG18-W--password Force clusterdb to prompt for a password before connecting to a database. This option is never essential, since clusterdb will automatically prompt for a password if the server …clusterdb › Options clusterdb --port=portCommand-line ToolsPG18-p port--port=port Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections.clusterdb › Options clusterdb --quietCommand-line ToolsPG18-q--quiet Do not display progress messages.clusterdb › Options clusterdb --table=tableCommand-line ToolsPG18-t table--table=table Cluster table only. Multiple tables can be clustered by writing multiple -t switches.clusterdb › Options clusterdb --username=usernameCommand-line ToolsPG18-U username--username=username User name to connect as.clusterdb › Options clusterdb --verboseCommand-line ToolsPG18-v--verbose Print detailed information during processing.clusterdb › Options clusterdb --versionCommand-line ToolsPG18-V--version Print the clusterdb version and exit.clusterdb › Options clusterdb [--dbname=]dbnameCommand-line ToolsPG18[-d] dbname[--dbname=]dbname Specifies the name of the database to be clustered, when -a/--all is not used. If this is not specified, the database name is read from the environment variable …clusterdb › Options cmathExtensionsExtensionsC11 math functions exposed to PostgreSQL with C-backed implementations. math postgres-cmath Functions and aggregatesFunctions and aggregates · Extensions cms_topnExtensionsExtensionsCount-min sketch data type and aggregates for approximate frequency and top-N queries cms_topn Functions and aggregatesFunctions and aggregates · Extensions COALESCESQL CommandsPG189.18.2. COALESCE # COALESCE(value [, ...]) The COALESCE function returns the first of its arguments that is not null. Null is returned only if all arguments are null. It is often used to sub…Conditional Expressions › COALESCE COALESCEManual ChaptersPG189.18.2. COALESCE COALESCE(value [, ...]) The COALESCE function returns the first of its arguments that is not null. Null is returned only if all arguments are null. It is often used to subst…COALESCE COALESCEFunctionsReferenceCOALESCE Conditional Expressions 10 The COALESCE function returns the first of its arguments that is not null. Null is returned only if all arguments are null. It is often used to substitute…Functions · Conditional Expressions Code TargetsManual ChaptersPG1817.4.4.1. Code Targets all # Build everything other than documentation backend # Build backend and related modules bin # Build frontend binaries contrib # Build contrib modules pl # Build pr…Code Targets col_descriptionFunctionsReferencecol_description System Information Functions And Operators 10 get comment for a table column col_description ( table_oid, column_number ) → text get comment for a table column 11 12 13 Retur…Functions · System Information Functions And Operators coldfrontExtensionsExtensionsTransparent hot and cold tiering between PostgreSQL partitions and writable Apache Iceberg tables beta dml-rewrite duckdb iceberg object-storage partitioning tiered-storage coldfront Analyti…Analytics · Extensions Collation ExpressionsManual ChaptersPG184.2.10. Collation Expressions The COLLATE clause overrides the collation of an expression. It is appended to the expression it applies to: expr COLLATE collation where collation is a possibl…Collation Expressions COLLATION FORSQL CommandsPG18COLLATION FOR ( "any" ) → text Returns the name of the collation of the value that is passed to it. The value is quoted and schema-qualified if necessary. If no collation was derived for the…System Information Functions and Operators › System Catalog Information Functions Collation Level ExamplesManual ChaptersPG1823.2.3.1.1. Collation Level Examples CREATE COLLATION level3 (provider = icu, deterministic = false, locale = 'und-u-ka-shifted-ks-level3'); CREATE COLLATION level4 (provider = icu, determin…Collation Level Examples Collation of PL/pgSQL VariablesManual ChaptersPG1841.3.6. Collation of PL/pgSQL Variables When a PL/pgSQL function has one or more parameters of collatable data types, a collation is identified for each function call depending on the collat…Collation of PL/pgSQL Variables Collation Settings ExamplesManual ChaptersPG1823.2.3.3. Collation Settings Examples CREATE COLLATION "de-u-co-phonebk-x-icu" (provider = icu, locale = 'de-u-co-phonebk'); # German collation with phone book collation type CREATE COLLATIO…Collation Settings Examples Collation Settings for an ICU LocaleManual ChaptersPG1823.2.3.2. Collation Settings for an ICU Locale Table 23.2 shows the available collation settings, which can be used as part of a language tag to customize a collation. Table 23.2. ICU Collat…Collation Settings for an ICU Locale Collation SupportManual ChaptersPG1823.2. Collation Support The collation feature allows specifying the sort order and character classification behavior of data per-column, or even per-operation. This alleviates the restrictio…Collation Support collation_character_set_​applicabilityManual ChaptersPG1835.11. collation_character_set_​applicability The view collation_character_set_applicability identifies which character set the available collations are applicable to. In PostgreSQL, there i…collation_character_set_​applicability collationsManual ChaptersPG1835.10. collations The view collations contains the collations available in the current database. Table 35.8. collations Columns Column Type Description collation_catalog sql_identifier Name …collations Collecting Crash DumpsManual ChaptersPG1817.7.3.1. Collecting Crash Dumps If PostgreSQL on Windows crashes, it has the ability to generate minidumps that can be used to track down the cause for the crash, similar to core dumps on U…Collecting Crash Dumps Collecting Crash DumpsManual ChaptersPG1817.7.5.3. Collecting Crash Dumps If PostgreSQL on Windows crashes, it has the ability to generate minidumps that can be used to track down the cause for the crash, similar to core dumps on U…Collecting Crash Dumps collectionExtensionsExtensionsAssociative-array data types for high-performance PL/pgSQL workflows pgcollection Data typesData types · Extensions colnamesExtensionsExtensionsLists the column names in a PostgreSQL RECORD value columns composite-type record colnames Functions and aggregatesFunctions and aggregates · Extensions cologne_pgExtensionsExtensionsCologne phonetics function for PostgreSQL built with pgrx. pgrx phonetics cologne_pg Full-text searchFull-text search · Extensions Color SupportManual ChaptersPG18Appendix N. Color Support Most programs in the PostgreSQL package can produce colorized console output. This appendix describes how that is configured.Color Support colorsExtensionsExtensionsC functions for perceptual color-distance calculations in the CIE L*a*b* color space similarity pg_colors Functions and aggregatesFunctions and aggregates · Extensions