NameALTER EVENT TRIGGER -- change the definition of an event trigger Synopsis ALTER EVENT TRIGGER name DISABLE ALTER EVENT TRIGGER name ENABLE [ REPLICA | ALWAYS ] ALTER EVENT TRIGGER name OWNER TO { new_owner | CURRENT_USER | SESSION_USER } ALTER EVENT TRIGGER name RENAME TO new_name Description ALTER EVENT TRIGGER changes properties of an existing event trigger. You must be superuser to alter an event trigger. Parameters name The name of an existing trigger to alter. new_owner

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

There are several settings which can cause the query planner not to generate a parallel query plan under any circumstances. In order for any parallel query plans whatsoever to be generated, the following settings must be configured as indicated. max_parallel_workers_per_gather must be set to a value which is greater than zero. This is a special case of the more general principle that no more workers should be used than the number configured via max_parallel_workers_per_gather. dynamic_shar

NameALTER COLLATION -- change the definition of a collation Synopsis ALTER COLLATION name RENAME TO new_name ALTER COLLATION name OWNER TO { new_owner | CURRENT_USER | SESSION_USER } ALTER COLLATION name SET SCHEMA new_schema Description ALTER COLLATION changes the definition of a collation. You must own the collation to use ALTER COLLATION. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have CREATE privilege on the collatio

NameCREATE FOREIGN DATA WRAPPER -- define a new foreign-data wrapper Synopsis CREATE FOREIGN DATA WRAPPER name [ HANDLER handler_function | NO HANDLER ] [ VALIDATOR validator_function | NO VALIDATOR ] [ OPTIONS ( option 'value' [, ... ] ) ] Description CREATE FOREIGN DATA WRAPPER creates a new foreign-data wrapper. The user who defines a foreign-data wrapper becomes its owner. The foreign-data wrapper name must be unique within the database. Only superusers can create fore

The view pg_stats provides access to the information stored in the pg_statistic catalog. This view allows access only to rows of pg_statistic that correspond to tables the user has permission to read, and therefore it is safe to allow public read access to this view. pg_stats is also designed to present the information in a more readable format than the underlying catalog — at the cost that its schema must be extended whenever new slot types are defined for pg_statistic. Table 50-78. pg_stats

GiST stands for Generalized Search Tree. It is a balanced, tree-structured access method, that acts as a base template in which to implement arbitrary indexing schemes. B-trees, R-trees and many other indexing schemes can be implemented in GiST. One advantage of GiST is that it allows the development of custom data types with the appropriate access methods, by an expert in the domain of the data type, rather than a database expert. Some of the information here is derived from the University of

The catalog pg_opfamily defines operator families. Each operator family is a collection of operators and associated support routines that implement the semantics specified for a particular index access method. Furthermore, the operators in a family are all "compatible", in a way that is specified by the access method. The operator family concept allows cross-data-type operators to be used with indexes and to be reasoned about using knowledge of access method semantics. Operator families are des

The view pg_file_settings provides a summary of the contents of the server's configuration file(s). A row appears in this view for each "name = value" entry appearing in the files, with annotations indicating whether the value could be applied successfully. Additional row(s) may appear for problems not linked to a "name = value" entry, such as syntax errors in the files. This view is helpful for checking whether planned changes in the configuration files will work, or for diagnosing a previous

Table 9-36 shows the operators available for the cidr and inet types. The operators <<, <<=, >>, >>=, and && test for subnet inclusion. They consider only the network parts of the two addresses (ignoring any host part) and determine whether one network is identical to or a subnet of the other. Table 9-36. cidr and inet Operators Operator Description Example < is less than inet '192.168.1.5' < inet '192.168.1.6' <= is less than or equal inet '192.168.1.