Class: ActiveRecord::ConnectionAdapters::PostgreSQLAdapter

Overview

The PostgreSQL adapter works with the native C (bitbucket.org/ged/ruby-pg) driver.

Options:

  • :host - Defaults to a Unix-domain socket in /tmp. On machines without Unix-domain sockets, the default is to connect to localhost.

  • :port - Defaults to 5432.

  • :username - Defaults to be the same as the operating system name of the user running the application.

  • :password - Password to be used if the server demands password authentication.

  • :database - Defaults to be the same as the user name.

  • :schema_search_path - An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the :schema_order option.

  • :encoding - An optional client encoding that is used in a SET client_encoding TO <encoding> call on the connection.

  • :min_messages - An optional client min messages that is used in a SET client_min_messages TO <min_messages> call on the connection.

  • :variables - An optional hash of additional parameters that will be used in SET SESSION key = val calls on the connection.

  • :insert_returning - An optional boolean to control the use of RETURNING for INSERT statements defaults to true.

Any further options are used as connection parameters to libpq. See www.postgresql.org/docs/current/static/libpq-connect.html for the list of parameters.

In addition, default connection parameters of libpq can be set per environment variables. See www.postgresql.org/docs/current/static/libpq-envars.html .

Defined Under Namespace

Classes: StatementPool

Constant Summary collapse

ADAPTER_NAME =
"PostgreSQL".freeze
NATIVE_DATABASE_TYPES =
{
  primary_key: "bigserial primary key",
  string:      { name: "character varying" },
  text:        { name: "text" },
  integer:     { name: "integer", limit: 4 },
  float:       { name: "float" },
  decimal:     { name: "decimal" },
  datetime:    { name: "timestamp" },
  time:        { name: "time" },
  date:        { name: "date" },
  daterange:   { name: "daterange" },
  numrange:    { name: "numrange" },
  tsrange:     { name: "tsrange" },
  tstzrange:   { name: "tstzrange" },
  int4range:   { name: "int4range" },
  int8range:   { name: "int8range" },
  binary:      { name: "bytea" },
  boolean:     { name: "boolean" },
  xml:         { name: "xml" },
  tsvector:    { name: "tsvector" },
  hstore:      { name: "hstore" },
  inet:        { name: "inet" },
  cidr:        { name: "cidr" },
  macaddr:     { name: "macaddr" },
  uuid:        { name: "uuid" },
  json:        { name: "json" },
  jsonb:       { name: "jsonb" },
  ltree:       { name: "ltree" },
  citext:      { name: "citext" },
  point:       { name: "point" },
  line:        { name: "line" },
  lseg:        { name: "lseg" },
  box:         { name: "box" },
  path:        { name: "path" },
  polygon:     { name: "polygon" },
  circle:      { name: "circle" },
  bit:         { name: "bit" },
  bit_varying: { name: "bit varying" },
  money:       { name: "money" },
  interval:    { name: "interval" },
  oid:         { name: "oid" },
}
OID =

:nodoc:

PostgreSQL::OID
OPERATION_ALIASES =

:nodoc:

{ # :nodoc:
  "maximum" => "max",
  "minimum" => "min",
  "average" => "avg",
}

Constants included from ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements

ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements::BYTEA_COLUMN_TYPE_OID, ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements::MONEY_COLUMN_TYPE_OID

Constants inherited from AbstractAdapter

AbstractAdapter::SIMPLE_INT

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#lock, #logger, #owner, #pool, #prepared_statements, #schema_cache, #visitor

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Attributes included from DatabaseStatements

#transaction_manager

Instance Method Summary collapse

Methods included from ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements

#begin_db_transaction, #begin_isolated_db_transaction, #commit_db_transaction, #exec_delete, #exec_insert, #exec_query, #exec_rollback_db_transaction, #execute, #explain, #query, #result_as_array

Methods included from ActiveRecord::ConnectionAdapters::PostgreSQL::SchemaStatements

#add_column, #add_index, #bulk_change_table, #change_column, #change_column_comment, #change_column_default, #change_column_null, #change_table_comment, #client_min_messages, #client_min_messages=, #collation, #columns_for_distinct, #create_database, #create_schema, #create_schema_dumper, #ctype, #current_database, #current_schema, #default_sequence_name, #drop_database, #drop_schema, #drop_table, #encoding, #foreign_keys, #foreign_table_exists?, #foreign_tables, #index_name_exists?, #indexes, #pk_and_sequence_for, #primary_keys, #recreate_database, #remove_index, #rename_column, #rename_index, #rename_table, #reset_pk_sequence!, #schema_exists?, #schema_names, #schema_search_path, #schema_search_path=, #serial_sequence, #set_pk_sequence!, #table_comment, #table_options, #type_to_sql, #update_table_definition, #validate_constraint, #validate_foreign_key

Methods included from ActiveRecord::ConnectionAdapters::PostgreSQL::ReferentialIntegrity

#disable_referential_integrity

Methods included from ActiveRecord::ConnectionAdapters::PostgreSQL::Quoting

#escape_bytea, #lookup_cast_type_from_column, #quote_column_name, #quote_default_expression, #quote_schema_name, #quote_string, #quote_table_name, #quote_table_name_for_assignment, #quoted_binary, #quoted_date, #unescape_bytea

Methods inherited from AbstractAdapter

#adapter_name, #case_insensitive_comparison, #case_sensitive_comparison, #close, #column_name_from_arel_node, #disable_referential_integrity, #expire, #lease, #migration_context, #migrations_paths, #prefetch_primary_key?, #raw_connection, #requires_reloading?, #seconds_idle, #steal!, #supports_comments_in_create?, #supports_multi_insert?, #supports_virtual_columns?, type_cast_config_to_boolean, type_cast_config_to_integer, #unprepared_statement, #valid_type?, #verify!

Methods included from Savepoints

#create_savepoint, #current_savepoint_name, #exec_rollback_to_savepoint, #release_savepoint

Methods included from QueryCache

#cache, #clear_query_cache, dirties_query_cache, #disable_query_cache!, #enable_query_cache!, included, #select_all, #uncached

Methods included from DatabaseLimits

#allowed_index_name_length, #column_name_length, #columns_per_multicolumn_index, #columns_per_table, #in_clause_length, #indexes_per_table, #joins_per_query, #sql_query_length, #table_name_length

Methods included from Quoting

#lookup_cast_type_from_column, #quote, #quote_column_name, #quote_default_expression, #quote_string, #quote_table_name, #quote_table_name_for_assignment, #quoted_binary, #quoted_date, #quoted_false, #quoted_time, #quoted_true, #type_cast, #type_cast_from_column, #type_casted_binds, #unquoted_false, #unquoted_true

Methods included from DatabaseStatements

#add_transaction_record, #begin_db_transaction, #begin_isolated_db_transaction, #cacheable_query, #commit_db_transaction, #default_sequence_name, #delete, #empty_insert_statement_value, #exec_delete, #exec_insert, #exec_query, #exec_rollback_db_transaction, #exec_update, #execute, #insert, #insert_fixture, #insert_fixtures, #insert_fixtures_set, #join_to_update, #query, #query_value, #query_values, #reset_sequence!, #reset_transaction, #rollback_db_transaction, #rollback_to_savepoint, #sanitize_limit, #select_all, #select_one, #select_rows, #select_value, #select_values, #supports_statement_cache?, #to_sql, #transaction, #transaction_isolation_levels, #transaction_open?, #transaction_state, #update

Methods included from SchemaStatements

#add_column, #add_foreign_key, #add_index, #add_index_options, #add_reference, #add_timestamps, #assume_migrated_upto_version, #change_column, #change_column_comment, #change_column_default, #change_column_null, #change_table, #change_table_comment, #column_exists?, #columns, #columns_for_distinct, #create_join_table, #create_schema_dumper, #create_table, #data_source_exists?, #data_sources, #drop_join_table, #drop_table, #dump_schema_information, #foreign_key_column_for, #foreign_key_exists?, #foreign_key_options, #foreign_keys, #index_exists?, #index_name, #index_name_exists?, #indexes, #internal_string_options_for_primary_key, #options_include_default?, #primary_key, #remove_column, #remove_columns, #remove_foreign_key, #remove_index, #remove_reference, #remove_timestamps, #rename_column, #rename_index, #rename_table, #table_alias_for, #table_comment, #table_exists?, #table_options, #tables, #type_to_sql, #update_table_definition, #view_exists?, #views

Constructor Details

#initialize(connection, logger, connection_parameters, config) ⇒ PostgreSQLAdapter

Initializes and connects a PostgreSQL adapter.


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 206

def initialize(connection, logger, connection_parameters, config)
  super(connection, logger, config)

  @connection_parameters = connection_parameters

  # @local_tz is initialized as nil to avoid warnings when connect tries to use it
  @local_tz = nil
  @max_identifier_length = nil

  connect
  add_pg_encoders
  @statements = StatementPool.new @connection,
                                  self.class.type_cast_config_to_integer(config[:statement_limit])

  if postgresql_version < 90100
    raise "Your version of PostgreSQL (#{postgresql_version}) is too old. Active Record supports PostgreSQL >= 9.1."
  end

  add_pg_decoders

  @type_map = Type::HashLookupTypeMap.new
  initialize_type_map
  @local_tz = execute("SHOW TIME ZONE", "SCHEMA").first["TimeZone"]
  @use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end

Instance Method Details

#active?Boolean

Is this connection alive and ready for queries?

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 244

def active?
  @lock.synchronize do
    @connection.query "SELECT 1"
  end
  true
rescue PG::Error
  false
end

#clear_cache!Object

Clears the prepared statements cache.


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 233

def clear_cache!
  @lock.synchronize do
    @statements.clear
  end
end

#column_name_for_operation(operation, node) ⇒ Object

:nodoc:


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 381

def column_name_for_operation(operation, node) # :nodoc:
  OPERATION_ALIASES.fetch(operation) { operation.downcase }
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 396

def default_index_type?(index) # :nodoc:
  index.using == :btree || super
end

#disable_extension(name) ⇒ Object


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 349

def disable_extension(name)
  exec_query("DROP EXTENSION IF EXISTS \"#{name}\" CASCADE").tap {
    reload_type_map
  }
end

#discard!Object

:nodoc:


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 283

def discard! # :nodoc:
  @connection.socket_io.reopen(IO::NULL) rescue nil
  @connection = nil
end

#disconnect!Object

Disconnects from the database if already connected. Otherwise, this method does nothing.


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 276

def disconnect!
  @lock.synchronize do
    super
    @connection.close rescue nil
  end
end

#enable_extension(name) ⇒ Object


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 343

def enable_extension(name)
  exec_query("CREATE EXTENSION IF NOT EXISTS \"#{name}\"").tap {
    reload_type_map
  }
end

#extension_enabled?(name) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 355

def extension_enabled?(name)
  res = exec_query("SELECT EXISTS(SELECT * FROM pg_available_extensions WHERE name = '#{name}' AND installed_version IS NOT NULL) as enabled", "SCHEMA")
  res.cast_values.first
end

#extensionsObject


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 360

def extensions
  exec_query("SELECT extname FROM pg_extension", "SCHEMA").cast_values
end

#get_advisory_lock(lock_id) ⇒ Object

:nodoc:


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 329

def get_advisory_lock(lock_id) # :nodoc:
  unless lock_id.is_a?(Integer) && lock_id.bit_length <= 63
    raise(ArgumentError, "PostgreSQL requires advisory lock ids to be a signed 64 bit integer")
  end
  query_value("SELECT pg_try_advisory_lock(#{lock_id})")
end

#index_algorithmsObject


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 173

def index_algorithms
  { concurrently: "CONCURRENTLY" }
end

#max_identifier_lengthObject Also known as: table_alias_length, index_name_length

Returns the configured supported identifier length supported by PostgreSQL


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 365

def max_identifier_length
  @max_identifier_length ||= query_value("SHOW max_identifier_length", "SCHEMA").to_i
end

#native_database_typesObject

:nodoc:


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 288

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#postgresql_versionObject

Returns the version of the connected PostgreSQL server.


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 392

def postgresql_version
  @connection.server_version
end

#reconnect!Object

Close then reopen the connection.


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 254

def reconnect!
  @lock.synchronize do
    super
    @connection.reset
    configure_connection
  end
end

#release_advisory_lock(lock_id) ⇒ Object

:nodoc:


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 336

def release_advisory_lock(lock_id) # :nodoc:
  unless lock_id.is_a?(Integer) && lock_id.bit_length <= 63
    raise(ArgumentError, "PostgreSQL requires advisory lock ids to be a signed 64 bit integer")
  end
  query_value("SELECT pg_advisory_unlock(#{lock_id})")
end

#reset!Object


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 262

def reset!
  @lock.synchronize do
    clear_cache!
    reset_transaction
    unless @connection.transaction_status == ::PG::PQTRANS_IDLE
      @connection.query "ROLLBACK"
    end
    @connection.query "DISCARD ALL"
    configure_connection
  end
end

#session_auth=(user) ⇒ Object

Set the authorized user for this session


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 372

def session_auth=(user)
  clear_cache!
  execute("SET SESSION AUTHORIZATION #{user}")
end

#set_standard_conforming_stringsObject


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 292

def set_standard_conforming_strings
  execute("SET standard_conforming_strings = on", "SCHEMA")
end

#supports_advisory_locks?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 300

def supports_advisory_locks?
  true
end

#supports_bulk_alter?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 125

def supports_bulk_alter?
  true
end

#supports_comments?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 165

def supports_comments?
  true
end

#supports_datetime_with_precision?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 157

def supports_datetime_with_precision?
  true
end

#supports_ddl_transactions?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 296

def supports_ddl_transactions?
  true
end

#supports_explain?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 304

def supports_explain?
  true
end

#supports_expression_index?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 137

def supports_expression_index?
  true
end

#supports_extensions?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 308

def supports_extensions?
  true
end

#supports_foreign_keys?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 145

def supports_foreign_keys?
  true
end

#supports_foreign_tables?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 321

def supports_foreign_tables?
  postgresql_version >= 90300
end

#supports_index_sort_order?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 129

def supports_index_sort_order?
  true
end

#supports_json?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 161

def supports_json?
  postgresql_version >= 90200
end

#supports_materialized_views?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 317

def supports_materialized_views?
  postgresql_version >= 90300
end

#supports_partial_index?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 133

def supports_partial_index?
  true
end

#supports_pgcrypto_uuid?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 325

def supports_pgcrypto_uuid?
  postgresql_version >= 90400
end

#supports_ranges?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 312

def supports_ranges?
  # Range datatypes weren't introduced until PostgreSQL 9.2
  postgresql_version >= 90200
end

#supports_savepoints?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 169

def supports_savepoints?
  true
end

#supports_transaction_isolation?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 141

def supports_transaction_isolation?
  true
end

#supports_validate_constraints?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 149

def supports_validate_constraints?
  true
end

#supports_views?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 153

def supports_views?
  true
end

#truncate(table_name, name = nil) ⇒ Object


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 239

def truncate(table_name, name = nil)
  exec_query "TRUNCATE TABLE #{quote_table_name(table_name)}", name, []
end

#use_insert_returning?Boolean

Returns:

  • (Boolean)

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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 377

def use_insert_returning?
  @use_insert_returning
end