NameREVOKE -- remove access privileges Synopsis REVOKE [ GRANT OPTION FOR ] { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER } [, ...] | ALL [ PRIVILEGES ] } ON { [ TABLE ] table_name [, ...] | ALL TABLES IN SCHEMA schema_name [, ...] } FROM { [ GROUP ] role_name | PUBLIC } [, ...] [ CASCADE | RESTRICT ] REVOKE [ GRANT OPTION FOR ] { { SELECT | INSERT | UPDATE | REFERENCES } ( column_name [, ...] ) [, ...] | ALL [ PRIVILEGES ] (

NameALTER SYSTEM -- change a server configuration parameter Synopsis ALTER SYSTEM SET configuration_parameter { TO | = } { value | 'value' | DEFAULT } ALTER SYSTEM RESET configuration_parameter ALTER SYSTEM RESET ALL Description ALTER SYSTEM is used for changing server configuration parameters across the entire database cluster. It can be more convenient than the traditional method of manually editing the postgresql.conf file. ALTER SYSTEM writes the given parameter setting to the po

The tsm_system_time module provides the table sampling method SYSTEM_TIME, which can be used in the TABLESAMPLE clause of a SELECT command. This table sampling method accepts a single floating-point argument that is the maximum number of milliseconds to spend reading the table. This gives you direct control over how long the query takes, at the price that the size of the sample becomes hard to predict. The resulting sample will contain as many rows as could be read in the specified time, unless

NameALTER TEXT SEARCH PARSER -- change the definition of a text search parser Synopsis ALTER TEXT SEARCH PARSER name RENAME TO new_name ALTER TEXT SEARCH PARSER name SET SCHEMA new_schema Description ALTER TEXT SEARCH PARSER changes the definition of a text search parser. Currently, the only supported functionality is to change the parser's name. You must be a superuser to use ALTER TEXT SEARCH PARSER. Parameters name The name (optionally schema-qualified) of an existing text sea

NameCREATE TEXT SEARCH PARSER -- define a new text search parser Synopsis CREATE TEXT SEARCH PARSER name ( START = start_function , GETTOKEN = gettoken_function , END = end_function , LEXTYPES = lextypes_function [, HEADLINE = headline_function ] ) Description CREATE TEXT SEARCH PARSER creates a new text search parser. A text search parser defines a method for splitting a text string into tokens and assigning types (categories) to the tokens. A parser is not partic

An index can support only one collation per index column. If multiple collations are of interest, multiple indexes may be needed. Consider these statements: CREATE TABLE test1c ( id integer, content varchar COLLATE "x" ); CREATE INDEX test1c_content_index ON test1c (content); The index automatically uses the collation of the underlying column. So a query of the form SELECT * FROM test1c WHERE content > constant; could use the index, because the comparison will by default use the

NameALTER LANGUAGE -- change the definition of a procedural language Synopsis ALTER [ PROCEDURAL ] LANGUAGE name RENAME TO new_name ALTER [ PROCEDURAL ] LANGUAGE name OWNER TO { new_owner | CURRENT_USER | SESSION_USER } Description ALTER LANGUAGE changes the definition of a procedural language. The only functionality is to rename the language or assign a new owner. You must be superuser or owner of the language to use ALTER LANGUAGE. Parameters name Name of a language new_name

NameDROP TYPE -- remove a data type Synopsis DROP TYPE [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ] Description DROP TYPE removes a user-defined data type. Only the owner of a type can remove it. Parameters IF EXISTS Do not throw an error if the type does not exist. A notice is issued in this case. name The name (optionally schema-qualified) of the data type to remove. CASCADE Automatically drop objects that depend on the type (such as table columns, functions, and opera

There are several WAL-related configuration parameters that affect database performance. This section explains their use. Consult Chapter 19 for general information about setting server configuration parameters. Checkpoints are points in the sequence of transactions at which it is guaranteed that the heap and index data files have been updated with all information written before that checkpoint. At checkpoint time, all dirty data pages are flushed to disk and a special checkpoint record is writ

exit_on_error (boolean) If true, any error will terminate the current session. By default, this is set to false, so that only FATAL errors will terminate the session. restart_after_crash (boolean) When set to true, which is the default, PostgreSQL will automatically reinitialize after a backend crash. Leaving this value set to true is normally the best way to maximize the availability of the database. However, in some circumstances, such as when PostgreSQL is being invoked by clusterware,