Class: ActiveRecord::ConnectionAdapters::RedshiftAdapter

Inherits:
AbstractAdapter
  • Object
show all
Includes:
DatabaseStatements, Quoting, ReferentialIntegrity, SchemaStatements
Defined in:
lib/active_record/connection_adapters/redshift_adapter.rb,
lib/active_record/connection_adapters/redshift/oid.rb,
lib/active_record/connection_adapters/redshift/quoting.rb,
lib/active_record/connection_adapters/redshift/schema_statements.rb,
lib/active_record/connection_adapters/redshift/database_statements.rb,
lib/active_record/connection_adapters/redshift/referential_integrity.rb

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 - does nothing for Redshift.

Any further options are used as connection parameters to libpq. See www.postgresql.org/docs/9.1/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/9.1/static/libpq-envars.html .

Defined Under Namespace

Modules: ColumnMethods, DatabaseStatements, OID, Quoting, ReferentialIntegrity, SchemaStatements, Utils Classes: BindSubstitution, ColumnDefinition, SchemaCreation, StatementPool, Table, TableDefinition

Constant Summary collapse

ADAPTER_NAME = 
'Redshift'
NATIVE_DATABASE_TYPES = 
{
  primary_key: "serial primary key",
  string:      { name: "character varying", limit: 255 },
  text:        { name: "text" },
  integer:     { name: "integer" },
  float:       { name: "float" },
  decimal:     { name: "decimal" },
  datetime:    { name: "timestamp" },
  timestamp:   { 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" },
  ltree:       { name: "ltree" }
}

Instance Method Summary collapse

Methods included from DatabaseStatements

#begin_db_transaction, #begin_isolated_db_transaction, #commit_db_transaction, #create, #create_savepoint, #exec_delete, #exec_insert, #exec_query, #execute, #explain, #insert_sql, #outside_transaction?, #query, #release_savepoint, #result_as_array, #rollback_db_transaction, #rollback_to_savepoint, #select_rows, #sql_for_insert, #substitute_at, #update_sql

Methods included from SchemaStatements

#add_column, #add_index, #change_column, #change_column_default, #change_column_null, #collation, #columns, #create_database, #create_schema, #ctype, #current_database, #current_schema, #default_sequence_name, #distinct, #drop_database, #drop_schema, #encoding, #index_name_length, #indexes, #pk_and_sequence_for, #primary_key, #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, #table_exists?, #tables, #type_to_sql

Methods included from ReferentialIntegrity

#disable_referential_integrity, #supports_disable_referential_integrity?

Methods included from Quoting

#escape_bytea, #quote, #quote_column_name, #quote_string, #quote_table_name, #quote_table_name_for_assignment, #quoted_date, #type_cast, #unescape_bytea

Constructor Details

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

Initializes and connects a PostgreSQL adapter.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 526

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

  if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
    @visitor = Arel::Visitors::PostgreSQL.new self
  else
    @visitor = unprepared_visitor
  end

  connection_parameters.delete :prepared_statements
  @connection_parameters, @config = connection_parameters, config

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

  connect
  @statements = StatementPool.new @connection,
                                  self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 })

  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]) : 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/redshift_adapter.rb', line 557

def active?
  @connection.connect_poll != PG::PGRES_POLLING_FAILED
rescue PGError
  false
end

#adapter_name ⇒ Object

Returns ‘PostgreSQL’ as adapter name for identification purposes.



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

def adapter_name
  ADAPTER_NAME
end

#clear_cache! ⇒ Object

Clears the prepared statements cache.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 552

def clear_cache!
  @statements.clear
end

#disable_extension(name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 631

def disable_extension(name)
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/redshift_adapter.rb', line 577

def disconnect!
  super
  @connection.close rescue nil
end

#enable_extension(name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 628

def enable_extension(name)
end

#extension_enabled?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 634

def extension_enabled?(name)
  false
end

#index_algorithms ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 464

def index_algorithms
  { concurrently: 'CONCURRENTLY' }
end

#migration_keys ⇒ Object

Adds ‘:array` as a valid migration key



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 442

def migration_keys
  super + [:array]
end

#native_database_types ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 582

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#prepare_column_options(column, types) ⇒ Object

Adds ‘:array` option to the default set provided by the AbstractAdapter



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 435

def prepare_column_options(column, types)
  spec = super
  spec[:array] = 'true' if column.respond_to?(:array) && column.array
  spec
end

#reconnect! ⇒ Object

Close then reopen the connection.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 564

def reconnect!
  super
  @connection.reset
  configure_connection
end

#reset! ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 570

def reset!
  clear_cache!
  super
end

#schema_creation ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 36

def schema_creation
  SchemaCreation.new self
end

#session_auth=(user) ⇒ Object

Set the authorized user for this session



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 647

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

#supports_ddl_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_ddl_transactions?
  true
end

#supports_explain? ⇒ Boolean

Returns true.

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 614

def supports_explain?
  true
end

#supports_extensions? ⇒ Boolean

Returns true if pg > 9.2

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 619

def supports_extensions?
  false
end

#supports_import? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 609

def supports_import?
  true
end

#supports_index_sort_order? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 452

def supports_index_sort_order?
  true
end

#supports_insert_with_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 596

def supports_insert_with_returning?
  false
end

#supports_migrations? ⇒ Boolean

Returns true, since this connection adapter supports migrations.

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 587

def supports_migrations?
  true
end

#supports_partial_index? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 456

def supports_partial_index?
  true
end

#supports_primary_key? ⇒ Boolean

Does PostgreSQL support finding primary key on non-Active Record tables?

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 592

def supports_primary_key? #:nodoc:
  true
end

#supports_ranges? ⇒ Boolean

Range datatypes weren’t introduced until PostgreSQL 9.2

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 624

def supports_ranges?
  false
end

#supports_savepoints? ⇒ Boolean

Returns true, since this connection adapter supports savepoints.

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 605

def supports_savepoints?
  false
end

#supports_statement_cache? ⇒ Boolean

Returns true, since this connection adapter supports prepared statement caching.

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 448

def supports_statement_cache?
  true
end

#supports_transaction_isolation? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 460

def supports_transaction_isolation?
  true
end

#table_alias_length ⇒ Object

Returns the configured supported identifier length supported by PostgreSQL



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 642

def table_alias_length
  @table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i
end

#use_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 671

def use_insert_returning?
  false
end

#valid_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 675

def valid_type?(type)
  !native_database_types[type].nil?
end