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"
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::COMMENT_REGEX, AbstractAdapter::SIMPLE_INT

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, #commit_db_transaction, #exec_delete, #exec_insert, #exec_query, #exec_rollback_db_transaction, #execute, #explain, #query, #result_as_array, #write_query?

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

#add_column, #add_index, #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

#column_name_matcher, #column_name_with_order_matcher, #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, #advisory_locks_enabled?, build_read_query_regexp, #case_insensitive_comparison, #case_sensitive_comparison, #clear_cache!, #close, #database_version, #default_uniqueness_comparison, #disable_referential_integrity, #expire, #lease, #migration_context, #migrations_paths, #prefetch_primary_key?, #prepared_statements, #prepared_statements_disabled_cache, #preventing_writes?, quoted_column_names, quoted_table_names, #raw_connection, #replica?, #requires_reloading?, #schema_cache, #schema_cache=, #schema_migration, #seconds_idle, #steal!, #supports_comments_in_create?, #supports_foreign_keys_in_create?, #supports_indexes_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, #index_name_length, #indexes_per_table, #joins_per_query, #sql_query_length, #table_alias_length, #table_name_length

Methods included from Quoting

#column_name_matcher, #column_name_with_order_matcher, #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, #sanitize_as_sql_comment, #type_cast, #type_cast_from_column, #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_rollback_db_transaction, #exec_update, #execute, #insert, #insert_fixture, #insert_fixtures_set, #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, #to_sql, #transaction, #transaction_isolation_levels, #transaction_open?, #transaction_state, #truncate, #truncate_tables, #update, #with_yaml_fallback, #write_query?

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 247

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

  configure_connection
  add_pg_encoders
  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

Class Method Details

.database_exists?(config) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 266

def self.database_exists?(config)
  !!ActiveRecord::Base.postgresql_connection(config)
rescue ActiveRecord::NoDatabaseError
  false
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 273

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

#build_insert_sql(insert) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 449

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 "
    sql << insert.updatable_columns.map { |column| "#{column}=excluded.#{column}" }.join(",")
  end

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

#check_versionObject

:nodoc:



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 463

def check_version # :nodoc:
  if database_version < 90300
    raise "Your version of PostgreSQL (#{database_version}) is too old. Active Record supports PostgreSQL >= 9.3."
  end
end

#column_name_for_operation(operation, node) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 429

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

#create_unlogged_tablesObject

: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 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 99

class_attribute :create_unlogged_tables, default: false

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 445

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 396

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 314

def discard! # :nodoc:
  super
  @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 307

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 390

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

#extension_available?(name) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 402

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 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 406

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

#extensionsObject



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 410

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 376

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_versionObject

Returns the version of the connected PostgreSQL server.



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 440

def get_database_version # :nodoc:
  @connection.server_version
end

#index_algorithmsObject



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 214

def index_algorithms
  { concurrently: "CONCURRENTLY" }
end

#max_identifier_lengthObject

Returns the configured supported identifier length supported by PostgreSQL



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 415

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 320

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#reconnect!Object

Close then reopen the connection.



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

def reconnect!
  @lock.synchronize do
    super
    @connection.reset
    configure_connection
  rescue PG::ConnectionBad
    connect
  end
end

#release_advisory_lock(lock_id) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 383

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 293

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 420

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 324

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 332

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 151

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 195

def supports_comments?
  true
end

#supports_common_table_expressions?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 368

def supports_common_table_expressions?
  true
end

#supports_datetime_with_precision?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 187

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 328

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 336

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 167

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 340

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 175

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 353

def supports_foreign_tables?
  true
end

#supports_index_sort_order?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 155

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 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 207

def supports_insert_on_conflict?
  database_version >= 90500
end

#supports_insert_returning?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 203

def supports_insert_returning?
  true
end

#supports_json?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 191

def supports_json?
  true
end

#supports_lazy_transactions?Boolean

Returns:

  • (Boolean)


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

def supports_lazy_transactions?
  true
end

#supports_materialized_views?Boolean

Returns:

  • (Boolean)


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

def supports_materialized_views?
  true
end

#supports_optimizer_hints?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 361

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 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 163

def supports_partial_index?
  true
end

#supports_partitioned_indexes?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 159

def supports_partitioned_indexes?
  database_version >= 110_000
end

#supports_pgcrypto_uuid?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 357

def supports_pgcrypto_uuid?
  database_version >= 90400
end

#supports_ranges?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 344

def supports_ranges?
  true
end

#supports_savepoints?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 199

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 171

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 179

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 183

def supports_views?
  true
end

#use_insert_returning?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 425

def use_insert_returning?
  @use_insert_returning
end