In an index scan, the index access method is responsible for regurgitating the TIDs of all the tuples it has been told about that match the scan keys. The access method is not involved in actually fetching those tuples from the index's parent table, nor in determining whether they pass the scan's time qualification test or other conditions. A scan key is the internal representation of a WHERE clause of the form index_key operator constant, where the index key is one of the columns of the index

NameALTER TYPE -- change the definition of a type Synopsis ALTER TYPE name action [, ... ] ALTER TYPE name OWNER TO { new_owner | CURRENT_USER | SESSION_USER } ALTER TYPE name RENAME ATTRIBUTE attribute_name TO new_attribute_name [ CASCADE | RESTRICT ] ALTER TYPE name RENAME TO new_name ALTER TYPE name SET SCHEMA new_schema ALTER TYPE name ADD VALUE [ IF NOT EXISTS ] new_enum_value [ { BEFORE | AFTER } existing_enum_value ] where action is one of: ADD ATTRIBUTE attribute_name data_t

NameALTER EXTENSION -- change the definition of an extension Synopsis ALTER EXTENSION name UPDATE [ TO new_version ] ALTER EXTENSION name SET SCHEMA new_schema ALTER EXTENSION name ADD member_object ALTER EXTENSION name DROP member_object where member_object is: AGGREGATE aggregate_name ( aggregate_signature ) | CAST (source_type AS target_type) | COLLATION object_name | CONVERSION object_name | DOMAIN object_name | EVENT TRIGGER object_name | FOREIGN DATA WRAPPER object_n

NameCREATE CAST -- define a new cast Synopsis CREATE CAST (source_type AS target_type) WITH FUNCTION function_name (argument_type [, ...]) [ AS ASSIGNMENT | AS IMPLICIT ] CREATE CAST (source_type AS target_type) WITHOUT FUNCTION [ AS ASSIGNMENT | AS IMPLICIT ] CREATE CAST (source_type AS target_type) WITH INOUT [ AS ASSIGNMENT | AS IMPLICIT ] Description CREATE CAST defines a new cast. A cast specifies how to perform a conversion between two data types. For e

bloom provides an index access method based on Bloom filters. A Bloom filter is a space-efficient data structure that is used to test whether an element is a member of a set. In the case of an index access method, it allows fast exclusion of non-matching tuples via signatures whose size is determined at index creation. A signature is a lossy representation of the indexed attribute(s), and as such is prone to reporting false positives; that is, it may be reported that an element is in the set, w

Namepg_dump -- extract a PostgreSQL database into a script file or other archive file Synopsis pg_dump [connection-option...] [option...] [dbname] Description pg_dump is a utility for backing up a PostgreSQL database. It makes consistent backups even if the database is being used concurrently. pg_dump does not block other users accessing the database (readers or writers). pg_dump only dumps a single database. To backup global objects that are common to all databases in a cluster, such a

The catalog pg_user_mapping stores the mappings from local user to remote. Access to this catalog is restricted from normal users, use the view pg_user_mappings instead. Table 50-57. pg_user_mapping Columns Name Type References Description oid oid Row identifier (hidden attribute; must be explicitly selected) umuser oid pg_authid.oid OID of the local role being mapped, 0 if the user mapping is public umserver oid pg_foreign_server.oid The OID of the foreign server that contains this mapping

NameCREATE OPERATOR CLASS -- define a new operator class Synopsis CREATE OPERATOR CLASS name [ DEFAULT ] FOR TYPE data_type USING index_method [ FAMILY family_name ] AS { OPERATOR strategy_number operator_name [ ( op_type, op_type ) ] [ FOR SEARCH | FOR ORDER BY sort_family_name ] | FUNCTION support_number [ ( op_type [ , op_type ] ) ] function_name ( argument_type [, ...] ) | STORAGE storage_type } [, ... ] Description CREATE OPERATOR CLASS creates a new operator class.

Database roles are conceptually completely separate from operating system users. In practice it might be convenient to maintain a correspondence, but this is not required. Database roles are global across a database cluster installation (and not per individual database). To create a role use the CREATE ROLE SQL command: CREATE ROLE name; name follows the rules for SQL identifiers: either unadorned without special characters, or double-quoted. (In practice, you will usually want to add additio

See Section 8.17 for an overview of range types. Table 9-49 shows the operators available for range types. Table 9-49. Range Operators Operator Description Example Result = equal int4range(1,5) = '[1,4]'::int4range t <> not equal numrange(1.1,2.2) <> numrange(1.1,2.3) t < less than int4range(1,10) < int4range(2,3) t > greater than int4range(1,10) > int4range(1,5) t <= less than or equal numrange(1.1,2.2) <= numrange(1.1,2.2) t >= greater than or equal numrange