Asynchronous commit is an option that allows transactions to complete more quickly, at the cost that the most recent transactions may be lost if the database should crash. In many applications this is an acceptable trade-off. As described in the previous section, transaction commit is normally synchronous: the server waits for the transaction's WAL records to be flushed to permanent storage before returning a success indication to the client. The client is therefore guaranteed that a transactio

Table 9-39, Table 9-40 and Table 9-41 summarize the functions and operators that are provided for full text searching. See Chapter 12 for a detailed explanation of PostgreSQL's text search facility. Table 9-39. Text Search Operators Operator Return Type Description Example Result @@ boolean tsvector matches tsquery ? to_tsvector('fat cats ate rats') @@ to_tsquery('cat & rat') t @@@ boolean deprecated synonym for @@ to_tsvector('fat cats ate rats') @@@ to_tsquery('cat & rat') t || ts

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

NameGRANT -- define access privileges Synopsis GRANT { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER } [, ...] | ALL [ PRIVILEGES ] } ON { [ TABLE ] table_name [, ...] | ALL TABLES IN SCHEMA schema_name [, ...] } TO role_specification [, ...] [ WITH GRANT OPTION ] GRANT { { SELECT | INSERT | UPDATE | REFERENCES } ( column_name [, ...] ) [, ...] | ALL [ PRIVILEGES ] ( column_name [, ...] ) } ON [ TABLE ] table_name [, ...] TO role_s

The fuzzystrmatch module provides several functions to determine similarities and distance between strings. Caution: At present, the soundex, metaphone, dmetaphone, and dmetaphone_alt functions do not work well with multibyte encodings (such as UTF-8). F.15.1. Soundex The Soundex system is a method of matching similar-sounding names by converting them to the same code. It was initially used by the United States Census in 1880, 1900, and 1910. Note that Soundex is not very useful for non-Engl

19.3.1. Connection Settings listen_addresses (string) Specifies the TCP/IP address(es) on which the server is to listen for connections from client applications. The value takes the form of a comma-separated list of host names and/or numeric IP addresses. The special entry * corresponds to all available IP interfaces. The entry 0.0.0.0 allows listening for all IPv4 addresses and :: allows listening for all IPv6 addresses. If the list is empty, the server does not listen on any IP interface

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

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

unaccent is a text search dictionary that removes accents (diacritic signs) from lexemes. It's a filtering dictionary, which means its output is always passed to the next dictionary (if any), unlike the normal behavior of dictionaries. This allows accent-insensitive processing for full text search. The current implementation of unaccent cannot be used as a normalizing dictionary for the thesaurus dictionary. F.44.1. Configuration An unaccent dictionary accepts the following options: RULES is

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