Class: ActiveRecord::ConnectionAdapters::PostgreSQLAdapter

Inherits:
AbstractAdapter show all
Includes:
ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements, ActiveRecord::ConnectionAdapters::PostgreSQL::Quoting, ActiveRecord::ConnectionAdapters::PostgreSQL::ReferentialIntegrity, ActiveRecord::ConnectionAdapters::PostgreSQL::SchemaStatements
Defined in:
activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

Overview

Active Record PostgreSQL Adapter

The PostgreSQL adapter works with the native C (github.com/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 username.

  • :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: MoneyDecoder, StatementPool

Constant Summary collapse

ADAPTER_NAME = 
"PostgreSQL"
NATIVE_DATABASE_TYPES = 
{
  primary_key: "bigserial primary key",
  string:      { name: "character varying" },
  text:        { name: "text" },
  integer:     { name: "integer", limit: 4 },
  bigint:      { name: "bigint" },
  float:       { name: "float" },
  decimal:     { name: "decimal" },
  datetime:    {}, # set dynamically based on datetime_type
  timestamp:   { name: "timestamp" },
  timestamptz: { name: "timestamptz" },
  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" },
  enum:        {} # special type https://www.postgresql.org/docs/current/datatype-enum.html
}
OID =

:nodoc:

PostgreSQL::OID

Constants included from ActiveRecord::ConnectionAdapters::PostgreSQL::Quoting

ActiveRecord::ConnectionAdapters::PostgreSQL::Quoting::QUOTED_COLUMN_NAMES, ActiveRecord::ConnectionAdapters::PostgreSQL::Quoting::QUOTED_TABLE_NAMES

Constants inherited from AbstractAdapter

AbstractAdapter::COMMENT_REGEX, AbstractAdapter::EXTENDED_TYPE_MAPS, AbstractAdapter::SIMPLE_INT, AbstractAdapter::TYPE_MAP

Constants included from QueryCache

QueryCache::DEFAULT_SIZE

Constants included from ActiveSupport::Callbacks

ActiveSupport::Callbacks::CALLBACK_FILTER_TYPES

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#lock, #logger, #owner, #pool, #visitor

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Attributes included from DatabaseStatements

#transaction_manager

Class Method Summary collapse

Instance Method Summary collapse

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

#begin_db_transaction, #begin_isolated_db_transaction, #build_explain_clause, #commit_db_transaction, #exec_delete, #exec_insert, #exec_restart_db_transaction, #exec_rollback_db_transaction, #execute, #explain, #high_precision_current_timestamp, #internal_exec_query, #query, #raw_execute, #write_query?

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

#add_column, #add_exclusion_constraint, #add_foreign_key, #add_index, #add_index_options, #add_unique_key, #build_change_column_default_definition, #build_change_column_definition, #build_create_index_definition, #change_column, #change_column_comment, #change_column_default, #change_column_null, #change_table_comment, #check_constraints, #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, #exclusion_constraint_options, #exclusion_constraints, #foreign_key_column_for, #foreign_keys, #foreign_table_exists?, #foreign_tables, #index_name, #index_name_exists?, #indexes, #pk_and_sequence_for, #primary_keys, #quoted_include_columns_for_index, #recreate_database, #remove_exclusion_constraint, #remove_index, #remove_unique_key, #rename_column, #rename_index, #rename_table, #reset_pk_sequence!, #schema_creation, #schema_exists?, #schema_names, #schema_search_path, #schema_search_path=, #serial_sequence, #set_pk_sequence!, #table_comment, #table_options, #type_to_sql, #unique_key_options, #unique_keys, #update_table_definition, #validate_check_constraint, #validate_constraint, #validate_foreign_key

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

#check_all_foreign_keys_valid!, #disable_referential_integrity

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

#check_int_in_range, #column_name_matcher, #column_name_with_order_matcher, #escape_bytea, #lookup_cast_type_from_column, #quote, #quote_column_name, #quote_default_expression, #quote_schema_name, #quote_string, #quote_table_name, #quote_table_name_for_assignment, #quoted_binary, #quoted_date, #type_cast, #unescape_bytea

Methods inherited from AbstractAdapter

#adapter_name, #advisory_locks_enabled?, #all_foreign_keys_valid?, #async_enabled?, build_read_query_regexp, #case_insensitive_comparison, #case_sensitive_comparison, #check_all_foreign_keys_valid!, #check_if_write_query, #clean!, #clear_cache!, #close, #connect!, #connection_class, #connection_retries, database_exists?, #database_exists?, #database_version, #default_timezone, #default_uniqueness_comparison, #disable_referential_integrity, #expire, extended_type_map, find_cmd_and_exec, #internal_metadata, #lease, #lock_thread=, #migration_context, #migrations_paths, #prefetch_primary_key?, #prepared_statements?, #prepared_statements_disabled_cache, #preventing_writes?, #raw_connection, #reconnect!, register_class_with_precision, #replica?, #requires_reloading?, #retry_deadline, #role, #savepoint_errors_invalidate_transactions?, #schema_cache, #schema_migration, #schema_version, #seconds_idle, #shard, #steal!, #supports_comments_in_create?, #supports_concurrent_connections?, #supports_indexes_in_create?, #throw_away!, type_cast_config_to_boolean, type_cast_config_to_integer, #unprepared_statement, #use_metadata_table?, #valid_type?, validate_default_timezone, #verify!, #with_instrumenter

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

#index_name_length, #table_alias_length

Methods included from Quoting

#cast_bound_value, #column_name_matcher, #column_name_with_order_matcher, #lookup_cast_type_from_column, #quote, #quote_bound_value, #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, #sanitize_as_sql_comment, #type_cast, #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_insert_all, #exec_query, #exec_restart_db_transaction, #exec_rollback_db_transaction, #exec_update, #execute, #explain, #high_precision_current_timestamp, #insert, #insert_fixture, #insert_fixtures_set, #internal_exec_query, #mark_transaction_written_if_write, #query, #query_value, #query_values, #reset_sequence!, #reset_transaction, #restart_db_transaction, #rollback_db_transaction, #rollback_to_savepoint, #sanitize_limit, #select_all, #select_one, #select_rows, #select_value, #select_values, #to_sql, #transaction, #transaction_isolation_levels, #transaction_open?, #truncate, #truncate_tables, #update, #with_yaml_fallback, #write_query?

Methods included from SchemaStatements

#add_check_constraint, #add_column, #add_columns, #add_foreign_key, #add_index, #add_index_options, #add_reference, #add_timestamps, #assume_migrated_upto_version, #build_add_column_definition, #build_change_column_default_definition, #build_create_index_definition, #build_create_join_table_definition, #build_create_table_definition, #bulk_change_table, #change_column, #change_column_comment, #change_column_default, #change_column_null, #change_table, #change_table_comment, #check_constraint_exists?, #check_constraint_options, #check_constraints, #column_exists?, #columns, #columns_for_distinct, #create_join_table, #create_schema_dumper, #create_table, #data_source_exists?, #data_sources, #distinct_relation_for_primary_key, #drop_join_table, #drop_table, #dump_schema_information, #foreign_key_column_for, #foreign_key_exists?, #foreign_key_options, #foreign_keys, #index_algorithm, #index_exists?, #index_name, #index_name_exists?, #indexes, #internal_string_options_for_primary_key, #max_index_name_size, #options_include_default?, #primary_key, #quoted_columns_for_index, #remove_check_constraint, #remove_column, #remove_columns, #remove_foreign_key, #remove_index, #remove_reference, #remove_timestamps, #rename_column, #rename_index, #rename_table, #schema_creation, #table_alias_for, #table_comment, #table_exists?, #table_options, #tables, #type_to_sql, #update_table_definition, #use_foreign_keys?, #valid_column_definition_options, #valid_primary_key_options, #valid_table_definition_options, #view_exists?, #views

Methods included from ActiveSupport::Callbacks

#run_callbacks

Methods included from ActiveSupport::Concern

#append_features, #class_methods, extended, #included, #prepend_features, #prepended

Constructor Details

#initialize ⇒ PostgreSQLAdapter

Initializes and connects a PostgreSQL adapter.



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

def initialize(...)
  super

  conn_params = @config.compact

  # Map ActiveRecords param names to PGs.
  conn_params[:user] = conn_params.delete(:username) if conn_params[:username]
  conn_params[:dbname] = conn_params.delete(:database) if conn_params[:database]

  # Forward only valid config params to PG::Connection.connect.
  valid_conn_param_keys = PG::Connection.conndefaults_hash.keys + [:requiressl]
  conn_params.slice!(*valid_conn_param_keys)

  @connection_parameters = conn_params

  @max_identifier_length = nil
  @type_map = nil
  @raw_connection = nil
  @notice_receiver_sql_warnings = []

  @use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end

Class Method Details

.dbconsole(config, options = {}) ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 84

def dbconsole(config, options = {})
  pg_config = config.configuration_hash

  ENV["PGUSER"]         = pg_config[:username] if pg_config[:username]
  ENV["PGHOST"]         = pg_config[:host] if pg_config[:host]
  ENV["PGPORT"]         = pg_config[:port].to_s if pg_config[:port]
  ENV["PGPASSWORD"]     = pg_config[:password].to_s if pg_config[:password] && options[:include_password]
  ENV["PGSSLMODE"]      = pg_config[:sslmode].to_s if pg_config[:sslmode]
  ENV["PGSSLCERT"]      = pg_config[:sslcert].to_s if pg_config[:sslcert]
  ENV["PGSSLKEY"]       = pg_config[:sslkey].to_s if pg_config[:sslkey]
  ENV["PGSSLROOTCERT"]  = pg_config[:sslrootcert].to_s if pg_config[:sslrootcert]
  if pg_config[:variables]
    ENV["PGOPTIONS"] = pg_config[:variables].filter_map do |name, value|
      "-c #{name}=#{value.to_s.gsub(/[ \\]/, '\\\\\0')}" unless value == ":default" || value == :default
    end.join(" ")
  end
  find_cmd_and_exec("psql", config.database)
end

.initialize_type_map(m) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 653

def initialize_type_map(m) # :nodoc:
  m.register_type "int2", Type::Integer.new(limit: 2)
  m.register_type "int4", Type::Integer.new(limit: 4)
  m.register_type "int8", Type::Integer.new(limit: 8)
  m.register_type "oid", OID::Oid.new
  m.register_type "float4", Type::Float.new
  m.alias_type "float8", "float4"
  m.register_type "text", Type::Text.new
  register_class_with_limit m, "varchar", Type::String
  m.alias_type "char", "varchar"
  m.alias_type "name", "varchar"
  m.alias_type "bpchar", "varchar"
  m.register_type "bool", Type::Boolean.new
  register_class_with_limit m, "bit", OID::Bit
  register_class_with_limit m, "varbit", OID::BitVarying
  m.register_type "date", OID::Date.new

  m.register_type "money", OID::Money.new
  m.register_type "bytea", OID::Bytea.new
  m.register_type "point", OID::Point.new
  m.register_type "hstore", OID::Hstore.new
  m.register_type "json", Type::Json.new
  m.register_type "jsonb", OID::Jsonb.new
  m.register_type "cidr", OID::Cidr.new
  m.register_type "inet", OID::Inet.new
  m.register_type "uuid", OID::Uuid.new
  m.register_type "xml", OID::Xml.new
  m.register_type "tsvector", OID::SpecializedString.new(:tsvector)
  m.register_type "macaddr", OID::Macaddr.new
  m.register_type "citext", OID::SpecializedString.new(:citext)
  m.register_type "ltree", OID::SpecializedString.new(:ltree)
  m.register_type "line", OID::SpecializedString.new(:line)
  m.register_type "lseg", OID::SpecializedString.new(:lseg)
  m.register_type "box", OID::SpecializedString.new(:box)
  m.register_type "path", OID::SpecializedString.new(:path)
  m.register_type "polygon", OID::SpecializedString.new(:polygon)
  m.register_type "circle", OID::SpecializedString.new(:circle)

  m.register_type "numeric" do |_, fmod, sql_type|
    precision = extract_precision(sql_type)
    scale = extract_scale(sql_type)

    # The type for the numeric depends on the width of the field,
    # so we'll do something special here.
    #
    # When dealing with decimal columns:
    #
    # places after decimal  = fmod - 4 & 0xffff
    # places before decimal = (fmod - 4) >> 16 & 0xffff
    if fmod && (fmod - 4 & 0xffff).zero?
      # FIXME: Remove this class, and the second argument to
      # lookups on PG
      Type::DecimalWithoutScale.new(precision: precision)
    else
      OID::Decimal.new(precision: precision, scale: scale)
    end
  end

  m.register_type "interval" do |*args, sql_type|
    precision = extract_precision(sql_type)
    OID::Interval.new(precision: precision)
  end
end

.native_database_types ⇒ Object

:nodoc:



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

def self.native_database_types # :nodoc:
  @native_database_types ||= begin
    types = NATIVE_DATABASE_TYPES.dup
    types[:datetime] = types[datetime_type]
    types
  end
end

.new_client(conn_params) ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 68

def new_client(conn_params)
  PG.connect(**conn_params)
rescue ::PG::Error => error
  if conn_params && conn_params[:dbname] == "postgres"
    raise ActiveRecord::ConnectionNotEstablished, error.message
  elsif conn_params && conn_params[:dbname] && error.message.include?(conn_params[:dbname])
    raise ActiveRecord::NoDatabaseError.db_error(conn_params[:dbname])
  elsif conn_params && conn_params[:user] && error.message.include?(conn_params[:user])
    raise ActiveRecord::DatabaseConnectionError.username_error(conn_params[:user])
  elsif conn_params && conn_params[:host] && error.message.include?(conn_params[:host])
    raise ActiveRecord::DatabaseConnectionError.hostname_error(conn_params[:host])
  else
    raise ActiveRecord::ConnectionNotEstablished, error.message
  end
end

Instance Method Details

#active? ⇒ Boolean

Is this connection alive and ready for queries?

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 341

def active?
  @lock.synchronize do
    return false unless @raw_connection
    @raw_connection.query ";"
  end
  true
rescue PG::Error
  false
end

#add_enum_value(type_name, value, options = {}) ⇒ Object

Add enum value to an existing enum type.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 565

def add_enum_value(type_name, value, options = {})
  before, after = options.values_at(:before, :after)
  sql = +"ALTER TYPE #{quote_table_name(type_name)} ADD VALUE '#{value}'"

  if before && after
    raise ArgumentError, "Cannot have both :before and :after at the same time"
  elsif before
    sql << " BEFORE '#{before}'"
  elsif after
    sql << " AFTER '#{after}'"
  end

  execute(sql).tap { reload_type_map }
end

#build_insert_sql(insert) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 627

def build_insert_sql(insert) # :nodoc:
  sql = +"INSERT #{insert.into} #{insert.values_list}"

  if insert.skip_duplicates?
    sql << " ON CONFLICT #{insert.conflict_target} DO NOTHING"
  elsif insert.update_duplicates?
    sql << " ON CONFLICT #{insert.conflict_target} DO UPDATE SET "
    if insert.raw_update_sql?
      sql << insert.raw_update_sql
    else
      sql << insert.touch_model_timestamps_unless { |column| "#{insert.model.quoted_table_name}.#{column} IS NOT DISTINCT FROM excluded.#{column}" }
      sql << insert.updatable_columns.map { |column| "#{column}=excluded.#{column}" }.join(",")
    end
  end

  sql << " RETURNING #{insert.returning}" if insert.returning
  sql
end

#check_version ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 646

def check_version # :nodoc:
  if database_version < 9_03_00 # < 9.3
    raise "Your version of PostgreSQL (#{database_version}) is too old. Active Record supports PostgreSQL >= 9.3."
  end
end

#create_enum(name, values, **options) ⇒ Object

Given a name and an array of values, creates an enum type.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 520

def create_enum(name, values, **options)
  sql_values = values.map { |s| quote(s) }.join(", ")
  scope = quoted_scope(name)
  query = <<~SQL
    DO $$
    BEGIN
        IF NOT EXISTS (
          SELECT 1
          FROM pg_type t
          JOIN pg_namespace n ON t.typnamespace = n.oid
          WHERE t.typname = #{scope[:name]}
            AND n.nspname = #{scope[:schema]}
        ) THEN
            CREATE TYPE #{quote_table_name(name)} AS ENUM (#{sql_values});
        END IF;
    END
    $$;
  SQL
  internal_exec_query(query)
end

#create_unlogged_tables ⇒ Object

:singleton-method: PostgreSQL allows the creation of “unlogged” tables, which do not record data in the PostgreSQL Write-Ahead Log. This can make the tables faster, but significantly increases the risk of data loss if the database crashes. As a result, this should not be used in production environments. If you would like all created tables to be unlogged in the test environment you can add the following line to your test.rb file:

ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.create_unlogged_tables = true



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 115

class_attribute :create_unlogged_tables, default: false

#datetime_type ⇒ Object

:singleton-method: PostgreSQL supports multiple types for DateTimes. By default, if you use datetime in migrations, Rails will translate this to a PostgreSQL “timestamp without time zone”. Change this in an initializer to use another NATIVE_DATABASE_TYPES. For example, to store DateTimes as “timestamp with time zone”:

ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.datetime_type = :timestamptz

Or if you are adding a custom type:

ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::NATIVE_DATABASE_TYPES[:my_custom_type] = { name: "my_custom_type_name" }
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.datetime_type = :my_custom_type

If you’re using :ruby as your config.active_record.schema_format and you change this setting, you should immediately run bin/rails db:migrate to update the types in your schema.rb.



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

class_attribute :datetime_type, default: :timestamp

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 623

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

#disable_extension(name, force: false) ⇒ Object

Removes an extension from the database.

:force

Set to :cascade to drop dependent objects as well. Defaults to false.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 478

def disable_extension(name, force: false)
  internal_exec_query("DROP EXTENSION IF EXISTS \"#{name}\"#{' CASCADE' if force == :cascade}").tap {
    reload_type_map
  }
end

#discard! ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 386

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

#disconnect! ⇒ Object

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



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 378

def disconnect!
  @lock.synchronize do
    super
    @raw_connection&.close rescue nil
    @raw_connection = nil
  end
end

#drop_enum(name, values = nil, **options) ⇒ Object

Drops an enum type.

If the if_exists: true option is provided, the enum is dropped only if it exists. Otherwise, if the enum doesn’t exist, an error is raised.

The values parameter will be ignored if present. It can be helpful to provide this in a migration’s change method so it can be reverted. In that case, values will be used by #create_enum.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 550

def drop_enum(name, values = nil, **options)
  query = <<~SQL
    DROP TYPE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(name)};
  SQL
  internal_exec_query(query)
end

#enable_extension(name) ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 465

def enable_extension(name, **)
  schema, name = name.to_s.split(".").values_at(-2, -1)
  sql = +"CREATE EXTENSION IF NOT EXISTS \"#{name}\""
  sql << " SCHEMA #{schema}" if schema

  internal_exec_query(sql).tap { reload_type_map }
end

#enum_types ⇒ Object

Returns a list of defined enum types, and their values.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 497

def enum_types
  query = <<~SQL
    SELECT
      type.typname AS name,
      type.OID AS oid,
      n.nspname AS schema,
      string_agg(enum.enumlabel, ',' ORDER BY enum.enumsortorder) AS value
    FROM pg_enum AS enum
    JOIN pg_type AS type ON (type.oid = enum.enumtypid)
    JOIN pg_namespace n ON type.typnamespace = n.oid
    WHERE n.nspname = ANY (current_schemas(false))
    GROUP BY type.OID, n.nspname, type.typname;
  SQL

  internal_exec_query(query, "SCHEMA", allow_retry: true, materialize_transactions: false).cast_values.each_with_object({}) do |row, memo|
    name, schema = row[0], row[2]
    schema = nil if schema == current_schema
    full_name = [schema, name].compact.join(".")
    memo[full_name] = row.last
  end.to_a
end

#extension_available?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 484

def extension_available?(name)
  query_value("SELECT true FROM pg_available_extensions WHERE name = #{quote(name)}", "SCHEMA")
end

#extension_enabled?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 488

def extension_enabled?(name)
  query_value("SELECT installed_version IS NOT NULL FROM pg_available_extensions WHERE name = #{quote(name)}", "SCHEMA")
end

#extensions ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 492

def extensions
  internal_exec_query("SELECT extname FROM pg_extension", "SCHEMA", allow_retry: true, materialize_transactions: false).cast_values
end

#get_advisory_lock(lock_id) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 451

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

#get_database_version ⇒ Object

Returns the version of the connected PostgreSQL server.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 618

def get_database_version # :nodoc:
  valid_raw_connection.server_version
end

#index_algorithms ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 284

def index_algorithms
  { concurrently: "CONCURRENTLY" }
end

#max_identifier_length ⇒ Object

Returns the configured supported identifier length supported by PostgreSQL



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 595

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

#native_database_types ⇒ Object

:nodoc:



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

def native_database_types # :nodoc:
  self.class.native_database_types
end

#release_advisory_lock(lock_id) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 458

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

#reload_type_map ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 351

def reload_type_map # :nodoc:
  @lock.synchronize do
    if @type_map
      type_map.clear
    else
      @type_map = Type::HashLookupTypeMap.new
    end

    initialize_type_map
  end
end

#rename_enum(name, options = {}) ⇒ Object

Rename an existing enum type to something else.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 558

def rename_enum(name, options = {})
  to = options.fetch(:to) { raise ArgumentError, ":to is required" }

  exec_query("ALTER TYPE #{quote_table_name(name)} RENAME TO #{to}").tap { reload_type_map }
end

#rename_enum_value(type_name, options = {}) ⇒ Object

Rename enum value on an existing enum type.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 581

def rename_enum_value(type_name, options = {})
  unless database_version >= 10_00_00 # >= 10.0
    raise ArgumentError, "Renaming enum values is only supported in PostgreSQL 10 or later"
  end

  from = options.fetch(:from) { raise ArgumentError, ":from is required" }
  to = options.fetch(:to) { raise ArgumentError, ":to is required" }

  execute("ALTER TYPE #{quote_table_name(type_name)} RENAME VALUE '#{from}' TO '#{to}'").tap {
    reload_type_map
  }
end

#reset! ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 363

def reset!
  @lock.synchronize do
    return connect! unless @raw_connection

    unless @raw_connection.transaction_status == ::PG::PQTRANS_IDLE
      @raw_connection.query "ROLLBACK"
    end
    @raw_connection.query "DISCARD ALL"

    super
  end
end

#return_value_after_insert?(column) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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

def return_value_after_insert?(column) # :nodoc:
  column.auto_populated?
end

#session_auth=(user) ⇒ Object

Set the authorized user for this session



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 608

def session_auth=(user)
  clear_cache!
  internal_execute("SET SESSION AUTHORIZATION #{user}", nil, materialize_transactions: true)
end

#set_standard_conforming_strings ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 404

def set_standard_conforming_strings
  internal_execute("SET standard_conforming_strings = on")
end

#supports_advisory_locks? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 412

def supports_advisory_locks?
  true
end

#supports_bulk_alter? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 189

def supports_bulk_alter?
  true
end

#supports_check_constraints? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 221

def supports_check_constraints?
  true
end

#supports_comments? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 253

def supports_comments?
  true
end

#supports_common_table_expressions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 443

def supports_common_table_expressions?
  true
end

#supports_datetime_with_precision? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 245

def supports_datetime_with_precision?
  true
end

#supports_ddl_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 408

def supports_ddl_transactions?
  true
end

#supports_deferrable_constraints? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 237

def supports_deferrable_constraints?
  true
end

#supports_exclusion_constraints? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 225

def supports_exclusion_constraints?
  true
end

#supports_explain? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 416

def supports_explain?
  true
end

#supports_expression_index? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 209

def supports_expression_index?
  true
end

#supports_extensions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 420

def supports_extensions?
  true
end

#supports_foreign_keys? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 217

def supports_foreign_keys?
  true
end

#supports_foreign_tables? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 428

def supports_foreign_tables?
  true
end

#supports_index_include? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 205

def supports_index_include?
  database_version >= 11_00_00 # >= 11.0
end

#supports_index_sort_order? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 193

def supports_index_sort_order?
  true
end

#supports_insert_on_conflict? ⇒ Boolean Also known as: supports_insert_on_duplicate_skip?, supports_insert_on_duplicate_update?, supports_insert_conflict_target?

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 269

def supports_insert_on_conflict?
  database_version >= 9_05_00 # >= 9.5
end

#supports_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 265

def supports_insert_returning?
  true
end

#supports_json? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 249

def supports_json?
  true
end

#supports_lazy_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 447

def supports_lazy_transactions?
  true
end

#supports_materialized_views? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 424

def supports_materialized_views?
  true
end

#supports_nulls_not_distinct? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 280

def supports_nulls_not_distinct?
  database_version >= 15_00_00 # >= 15.0
end

#supports_optimizer_hints? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 436

def supports_optimizer_hints?
  unless defined?(@has_pg_hint_plan)
    @has_pg_hint_plan = extension_available?("pg_hint_plan")
  end
  @has_pg_hint_plan
end

#supports_partial_index? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 201

def supports_partial_index?
  true
end

#supports_partitioned_indexes? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 197

def supports_partitioned_indexes?
  database_version >= 11_00_00 # >= 11.0
end

#supports_pgcrypto_uuid? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 432

def supports_pgcrypto_uuid?
  database_version >= 9_04_00 # >= 9.4
end

#supports_restart_db_transaction? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 261

def supports_restart_db_transaction?
  database_version >= 12_00_00 # >= 12.0
end

#supports_savepoints? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 257

def supports_savepoints?
  true
end

#supports_transaction_isolation? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 213

def supports_transaction_isolation?
  true
end

#supports_unique_keys? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 229

def supports_unique_keys?
  true
end

#supports_validate_constraints? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_validate_constraints?
  true
end

#supports_views? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 241

def supports_views?
  true
end

#supports_virtual_columns? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_virtual_columns?
  database_version >= 12_00_00 # >= 12.0
end

#table_name_length ⇒ Object

Returns the maximum length of a table name.



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 600

def table_name_length
  # PostgreSQL automatically creates an index for PRIMARY KEY with name consisting of
  # truncated table name and "_pkey" suffix fitting into max_identifier_length number of characters.
  # We allow smaller table names to be able to correctly rename this index when renaming the table.
  max_identifier_length - "_pkey".length
end

#use_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 613

def use_insert_returning?
  @use_insert_returning
end