Class: ActiveRecord::ConnectionAdapters::RedshiftAdapter

Inherits:
AbstractAdapter
  • Object
show all
Defined in:
lib/active_record/connection_adapters/redshift_adapter.rb

Overview

The Redshift adapter works both with the native C (ruby.scripting.ca/postgres/) and the pure Ruby (available both as gem and from rubyforge.org/frs/?group_id=234&release_id=1944) drivers.

Options:

  • :host - Defaults to “localhost”.

  • :port - Defaults to 5432.

  • :username - Defaults to nothing.

  • :password - Defaults to nothing.

  • :database - The name of the database. No default, must be provided.

  • :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.

Defined Under Namespace

Modules: Utils Classes: BindSubstitution, ExplainPrettyPrinter, StatementPool, TableDefinition

Constant Summary collapse

ADAPTER_NAME = 
'Redshift'
NATIVE_DATABASE_TYPES = 
{
  :primary_key => "bigint 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" },
  :binary      => { :name => "bytea" },
  :boolean     => { :name => "boolean" },
  :xml         => { :name => "xml" },
  :tsvector    => { :name => "tsvector" }
}

Instance Method Summary collapse

Constructor Details

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

Initializes and connects a Redshift adapter.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 340

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

  if config.fetch(:prepared_statements) { true }
    @visitor = Arel::Visitors::PostgreSQL.new self
  else
    @visitor = BindSubstitution.new self
  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,
                                  config.fetch(:statement_limit) { 1000 }

  if redshift_version < 80002
    raise "Your version of Redshift (#{redshift_version}) is too old, please upgrade!"
  end

  @local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
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 374

def active?
  @connection.query 'SELECT 1'
  true
rescue PGError
  false
end

#adapter_name ⇒ Object

Returns ‘Redshift’ as adapter name for identification purposes.



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

def adapter_name
  ADAPTER_NAME
end

#add_column(table_name, column_name, type, options = {}) ⇒ Object

Adds a new column to the named table. See TableDefinition#column for details of the options you can use.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1006

def add_column(table_name, column_name, type, options = {})
  clear_cache!
  add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(add_column_sql, options)

  execute add_column_sql
end

#add_index ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1045

def add_index(*)
  # XXX nothing to do
end

#begin_db_transaction ⇒ Object

Begins a transaction.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 726

def begin_db_transaction
  execute "BEGIN"
end

#change_column(table_name, column_name, type, options = {}) ⇒ Object

Changes the column of a table.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1015

def change_column(table_name, column_name, type, options = {})
  clear_cache!
  quoted_table_name = quote_table_name(table_name)

  execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"

  change_column_default(table_name, column_name, options[:default]) if options_include_default?(options)
  change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
end

#change_column_default(table_name, column_name, default) ⇒ Object

Changes the default value of a table column.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1026

def change_column_default(table_name, column_name, default)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}"
end

#change_column_null(table_name, column_name, null, default = nil) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1031

def change_column_null(table_name, column_name, null, default = nil)
  clear_cache!
  unless null || default.nil?
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
  end
  execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
end

#clear_cache! ⇒ Object

Clears the prepared statements cache.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 369

def clear_cache!
  @statements.clear
end

#columns(table_name, name = nil) ⇒ Object

Returns the list of all column definitions for a table.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 851

def columns(table_name, name = nil)
  # Limit, precision, and scale are all handled by the superclass.
  column_definitions(table_name).collect do |column_name, type, default, notnull|
    RedshiftColumn.new(column_name, default, type, notnull == 'f', @config[:read_timezone])
  end
end

#commit_db_transaction ⇒ Object

Commits a transaction.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 731

def commit_db_transaction
  execute "COMMIT"
end

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

Create a new Redshift database. Options include :owner, :template, :encoding, :tablespace, and :connection_limit (note that MySQL uses :charset while Redshift uses :encoding).

Example:

create_database config[:database], config
create_database 'foo_development', :encoding => 'unicode'



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 776

def create_database(name, options = {})
  options = options.reverse_merge(:encoding => "utf8")

  option_string = options.symbolize_keys.sum do |key, value|
    case key
    when :owner
      " OWNER = \"#{value}\""
    when :template
      " TEMPLATE = \"#{value}\""
    when :encoding
      " ENCODING = '#{value}'"
    when :tablespace
      " TABLESPACE = \"#{value}\""
    when :connection_limit
      " CONNECTION LIMIT = #{value}"
    else
      ""
    end
  end

  execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
end

#create_savepoint ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 744

def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end

#current_database ⇒ Object

Returns the current database name.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 859

def current_database
  query('select current_database()', 'SCHEMA')[0][0]
end

#current_schema ⇒ Object

Returns the current schema name.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 864

def current_schema
  query('SELECT current_schema', 'SCHEMA')[0][0]
end

#default_sequence_name(table_name, pk = nil) ⇒ Object

Returns the sequence name for a table’s primary key or some other specified key.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 894

def default_sequence_name(table_name, pk = nil) #:nodoc:
  serial_sequence(table_name, pk || 'id').split('.').last
rescue ActiveRecord::StatementInvalid
  "#{table_name}_#{pk || 'id'}_seq"
end

#disable_referential_integrity ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 544

def disable_referential_integrity #:nodoc:
  if supports_disable_referential_integrity? then
    execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} DISABLE TRIGGER ALL" }.join(";"))
  end
  yield
ensure
  if supports_disable_referential_integrity? then
    execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} ENABLE TRIGGER ALL" }.join(";"))
  end
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 396

def disconnect!
  clear_cache!
  @connection.close rescue nil
end

#distinct(columns, orders) ⇒ Object

Returns a SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.

Redshift requires the ORDER BY columns in the select list for distinct queries, and requires that the ORDER BY include the distinct column.

distinct("posts.id", "posts.created_at desc")



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1089

def distinct(columns, orders) #:nodoc:
  return "DISTINCT #{columns}" if orders.empty?

  # Construct a clean list of column names from the ORDER BY clause, removing
  # any ASC/DESC modifiers
  order_columns = orders.collect { |s| s.gsub(/\s+(ASC|DESC)\s*(NULLS\s+(FIRST|LAST)\s*)?/i, '') }
  order_columns.delete_if { |c| c.blank? }
  order_columns = order_columns.zip((0...order_columns.size).to_a).map { |s,i| "#{s} AS alias_#{i}" }

  "DISTINCT #{columns}, #{order_columns * ', '}"
end

#drop_database(name) ⇒ Object

Drops a Redshift database.

Example:

drop_database 'matt_development'



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 803

def drop_database(name) #:nodoc:
  execute "DROP DATABASE IF EXISTS #{quote_table_name(name)}"
end

#encoding ⇒ Object

Returns the current database encoding format.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 869

def encoding
  query("    SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database\n    WHERE pg_database.datname LIKE '\#{current_database}'\n  end_sql\nend\n", 'SCHEMA')[0][0]

#escape_bytea(value) ⇒ Object

Escapes binary strings for bytea input to the database.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 441

def escape_bytea(value)
  @connection.escape_bytea(value) if value
end

#exec_delete(sql, name = 'SQL', binds = []) ⇒ Object Also known as: exec_update 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 697

def exec_delete(sql, name = 'SQL', binds = [])
  log(sql, name, binds) do
    result = binds.empty? ? exec_no_cache(sql, binds) :
                            exec_cache(sql, binds)
    affected = result.cmd_tuples
    result.clear
    affected
  end
end

#exec_query(sql, name = 'SQL', binds = []) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 686

def exec_query(sql, name = 'SQL', binds = [])
  log(sql, name, binds) do
    result = binds.empty? ? exec_no_cache(sql, binds) :
                            exec_cache(sql, binds)

    ret = ActiveRecord::Result.new(result.fields, result_as_array(result))
    result.clear
    return ret
  end
end

#execute(sql, name = nil) ⇒ Object

Executes an SQL statement, returning a PGresult object on success or raising a PGError exception otherwise.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 676

def execute(sql, name = nil)
  log(sql, name) do
    @connection.async_exec(sql)
  end
end

#explain(arel, binds = []) ⇒ Object

DATABASE STATEMENTS ======================================



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 557

def explain(arel, binds = [])
  sql = "EXPLAIN #{to_sql(arel, binds)}"
  ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds))
end

#index_name_length ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1055

def index_name_length
  63
end

#indexes(table_name, name = nil) ⇒ Object

Returns an array of indexes for the given table.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 846

def indexes(table_name, name = nil)
  []
end

#insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object

Executes an INSERT query and returns the new record’s ID



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 606

def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
  unless pk
    # Extract the table from the insert sql. Yuck.
    table_ref = extract_table_ref_from_insert_sql(sql)
    pk = primary_key(table_ref) if table_ref
  end
  
  if pk && use_insert_returning?
    select_value("#{sql} RETURNING #{quote_column_name(pk)}")
  elsif pk
    super
    last_insert_id_value(sequence_name || default_sequence_name(table_ref, pk))
  else
    super
  end
end

#native_database_types ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 401

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#outside_transaction? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 740

def outside_transaction?
  @connection.transaction_status == PGconn::PQTRANS_IDLE
end

#pk_and_sequence_for(table) ⇒ Object

Returns a table’s primary key and belonging sequence.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 930

def pk_and_sequence_for(table) #:nodoc:
  # First try looking for a sequence with a dependency on the
  # given table's primary key.
  result = query("    SELECT attr.attname, seq.relname\n    FROM pg_class      seq,\n         pg_attribute  attr,\n         pg_depend     dep,\n         pg_namespace  name,\n         pg_constraint cons\n    WHERE seq.oid           = dep.objid\n      AND seq.relkind       = 'S'\n      AND attr.attrelid     = dep.refobjid\n      AND attr.attnum       = dep.refobjsubid\n      AND attr.attrelid     = cons.conrelid\n      AND attr.attnum       = cons.conkey[1]\n      AND cons.contype      = 'p'\n      AND dep.refobjid      = '\#{quote_table_name(table)}'::regclass\n  end_sql\n\n  if result.nil? or result.empty?\n    result = query(<<-end_sql, 'SCHEMA')[0]\n      SELECT attr.attname,\n        CASE\n          WHEN split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2) ~ '.' THEN\n            substr(split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2),\n                   strpos(split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2), '.')+1)\n          ELSE split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2)\n        END\n      FROM pg_class       t\n      JOIN pg_attribute   attr ON (t.oid = attrelid)\n      JOIN pg_attrdef     def  ON (adrelid = attrelid AND adnum = attnum)\n      JOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])\n      WHERE t.oid = '\#{quote_table_name(table)}'::regclass\n        AND cons.contype = 'p'\n        AND pg_get_expr(def.adbin, def.adrelid) ~* 'nextval'\n    end_sql\n  end\n\n  [result.first, result.last]\nrescue\n  nil\nend\n", 'SCHEMA')[0]

#primary_key(table) ⇒ Object

Returns just a table’s primary key



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 975

def primary_key(table)
  row = exec_query("    SELECT DISTINCT(attr.attname)\n    FROM pg_attribute attr\n    INNER JOIN pg_depend dep ON attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid\n    INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1]\n    WHERE cons.contype = 'p'\n      AND dep.refobjid = '\#{quote_table_name(table)}'::regclass\n  end_sql\n\n  row && row.first\nend\n", 'SCHEMA').rows.first

#query(sql, name = nil) ⇒ Object

Queries the database and returns the results in an Array-like object



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 668

def query(sql, name = nil) #:nodoc:
  log(sql, name) do
    result_as_array @connection.async_exec(sql)
  end
end

#quote(value, column = nil) ⇒ Object

Quotes Redshift-specific data types for SQL input.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 453

def quote(value, column = nil) #:nodoc:
  return super unless column

  case value
  when Float
    return super unless value.infinite? && column.type == :datetime
    "'#{value.to_s.downcase}'"
  when Numeric
    return super unless column.sql_type == 'money'
    # Not truly string input, so doesn't require (or allow) escape string syntax.
    "'#{value}'"
  when String
    case column.sql_type
    when 'bytea' then "'#{escape_bytea(value)}'"
    when 'xml'   then "xml '#{quote_string(value)}'"
    when /^bit/
      case value
      when /^[01]*$/      then "B'#{value}'" # Bit-string notation
      when /^[0-9A-F]*$/i then "X'#{value}'" # Hexadecimal notation
      end
    else
      super
    end
  else
    super
  end
end

#quote_column_name(name) ⇒ Object

Quotes column names for use in SQL queries.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 518

def quote_column_name(name) #:nodoc:
  PGconn.quote_ident(name.to_s)
end

#quote_string(s) ⇒ Object

Quotes strings for use in SQL input.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 494

def quote_string(s) #:nodoc:
  @connection.escape(s)
end

#quote_table_name(name) ⇒ Object

Checks the following cases:

  • table_name

  • “table.name”

  • schema_name.table_name

  • schema_name.“table.name”

  • “schema.name”.table_name

  • “schema.name”.“table.name”



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 506

def quote_table_name(name)
  schema, name_part = extract_pg_identifier_from_name(name.to_s)

  unless name_part
    quote_column_name(schema)
  else
    table_name, name_part = extract_pg_identifier_from_name(name_part)
    "#{quote_column_name(schema)}.#{quote_column_name(table_name)}"
  end
end

#quoted_date(value) ⇒ Object

Quote date/time values for use in SQL input. Includes microseconds if the value is a Time responding to usec.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 524

def quoted_date(value) #:nodoc:
  if value.acts_like?(:time) && value.respond_to?(:usec)
    "#{super}.#{sprintf("%06d", value.usec)}"
  else
    super
  end
end

#reconnect! ⇒ Object

Close then reopen the connection.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 382

def reconnect!
  clear_cache!
  @connection.reset
  @open_transactions = 0
  configure_connection
end

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

Drops the database specified on the name attribute and creates it again using the provided options.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 764

def recreate_database(name, options = {}) #:nodoc:
  drop_database(name)
  create_database(name, options)
end

#release_savepoint ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 752

def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end

#remove_index!(table_name, index_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1049

def remove_index!(table_name, index_name) #:nodoc:
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

Renames a column in a table.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1040

def rename_column(table_name, column_name, new_column_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
end

#rename_index(table_name, old_name, new_name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1052

def rename_index(table_name, old_name, new_name)
end

#rename_table(name, new_name) ⇒ Object

Renames a table. Also renames a table’s primary key sequence if the sequence name matches the Active Record default.

Example:

rename_table('octopuses', 'octopi')



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 994

def rename_table(name, new_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
  pk, seq = pk_and_sequence_for(new_name)
  if seq == "#{name}_#{pk}_seq"
    new_seq = "#{new_name}_#{pk}_seq"
    execute "ALTER TABLE #{quote_table_name(seq)} RENAME TO #{quote_table_name(new_seq)}"
  end
end

#reset! ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 389

def reset!
  clear_cache!
  super
end

#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object

Resets the sequence of a table’s primary key to the maximum value.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 908

def reset_pk_sequence!(table, pk = nil, sequence = nil) #:nodoc:
  unless pk and sequence
    default_pk, default_sequence = pk_and_sequence_for(table)

    pk ||= default_pk
    sequence ||= default_sequence
  end

  if @logger && pk && !sequence
    @logger.warn "#{table} has primary key #{pk} with no default sequence"
  end

  if pk && sequence
    quoted_sequence = quote_table_name(sequence)

    select_value "      SELECT setval('\#{quoted_sequence}', (SELECT COALESCE(MAX(\#{quote_column_name pk})+(SELECT increment_by FROM \#{quoted_sequence}), (SELECT min_value FROM \#{quoted_sequence})) FROM \#{quote_table_name(table)}), false)\n    end_sql\n  end\nend\n", 'SCHEMA'

#result_as_array(res) ⇒ Object

create a 2D array representing the result set



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 625

def result_as_array(res) #:nodoc:
  # check if we have any binary column and if they need escaping
  ftypes = Array.new(res.nfields) do |i|
    [i, res.ftype(i)]
  end

  rows = res.values
  return rows unless ftypes.any? { |_, x|
    x == BYTEA_COLUMN_TYPE_OID || x == MONEY_COLUMN_TYPE_OID
  }

  typehash = ftypes.group_by { |_, type| type }
  binaries = typehash[BYTEA_COLUMN_TYPE_OID] || []
  monies   = typehash[MONEY_COLUMN_TYPE_OID] || []

  rows.each do |row|
    # unescape string passed BYTEA field (OID == 17)
    binaries.each do |index, _|
      row[index] = unescape_bytea(row[index])
    end

    # If this is a money type column and there are any currency symbols,
    # then strip them off. Indeed it would be prettier to do this in
    # RedshiftColumn.string_to_decimal but would break form input
    # fields that call value_before_type_cast.
    monies.each do |index, _|
      data = row[index]
      # Because money output is formatted according to the locale, there are two
      # cases to consider (note the decimal separators):
      #  (1) $12,345,678.12
      #  (2) $12.345.678,12
      case data
      when /^-?\D+[\d,]+\.\d{2}$/  # (1)
        data.gsub!(/[^-\d.]/, '')
      when /^-?\D+[\d.]+,\d{2}$/  # (2)
        data.gsub!(/[^-\d,]/, '').sub!(/,/, '.')
      end
    end
  end
end

#rollback_db_transaction ⇒ Object

Aborts a transaction.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 736

def rollback_db_transaction
  execute "ROLLBACK"
end

#rollback_to_savepoint ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 748

def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end

#schema_exists?(name) ⇒ Boolean

Returns true if schema exists.

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 837

def schema_exists?(name)
  exec_query("    SELECT COUNT(*)\n    FROM pg_namespace\n    WHERE nspname = '\#{name}'\n  SQL\nend\n", 'SCHEMA').rows.first[0].to_i > 0

#schema_search_path ⇒ Object

Returns the active schema search path.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 889

def schema_search_path
  @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0]
end

#schema_search_path=(schema_csv) ⇒ Object

Sets the schema search path to a string of comma-separated schema names. Names beginning with $ have to be quoted (e.g. $user => ‘$user’). See: www.redshift.org/docs/current/static/ddl-schemas.html

This should be not be called manually but set in database.yml.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 881

def schema_search_path=(schema_csv)
  if schema_csv
    execute("SET search_path TO #{schema_csv}", 'SCHEMA')
    @schema_search_path = schema_csv
  end
end

#select_rows(sql, name = nil) ⇒ Object

Executes a SELECT query and returns an array of rows. Each row is an array of field values.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 601

def select_rows(sql, name = nil)
  select_raw(sql, name).last
end

#serial_sequence(table, column) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 900

def serial_sequence(table, column)
  result = exec_query("    SELECT pg_get_serial_sequence('\#{table}', '\#{column}')\n  eosql\n  result.rows.first.first\nend\n", 'SCHEMA')

#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 533

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

#sql_for_insert(sql, pk, id_value, sequence_name, binds) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 708

def sql_for_insert(sql, pk, id_value, sequence_name, binds)
  unless pk
    # Extract the table from the insert sql. Yuck.
    table_ref = extract_table_ref_from_insert_sql(sql)
    pk = primary_key(table_ref) if table_ref
  end

  sql = "#{sql} RETURNING #{quote_column_name(pk)}" if pk && use_insert_returning?

  [sql, binds]
end

#substitute_at(column, index) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 682

def substitute_at(column, index)
  Arel::Nodes::BindParam.new "$#{index + 1}"
end

#supports_ddl_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 419

def supports_ddl_transactions?
  true
end

#supports_disable_referential_integrity? ⇒ Boolean

REFERENTIAL INTEGRITY ====================================

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 540

def supports_disable_referential_integrity? #:nodoc:
  false
end

#supports_explain? ⇒ Boolean

Returns true.

Returns:

  • (Boolean) 


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

def supports_explain?
  true
end

#supports_index_sort_order? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 279

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 415

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 406

def supports_migrations?
  true
end

#supports_primary_key? ⇒ Boolean

Does Redshift 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 411

def supports_primary_key? #:nodoc:
  true
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 424

def supports_savepoints?
  true
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 275

def supports_statement_cache?
  true
end

#table_alias_length ⇒ Object

Returns the configured supported identifier length supported by Redshift



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 434

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

#table_exists?(name) ⇒ Boolean

Returns true if table exists. If the schema is not specified as part of name then it will only find tables within the current schema search path (regardless of permissions to access tables in other schemas)

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 819

def table_exists?(name)
  schema, table = Utils.extract_schema_and_table(name.to_s)
  return false unless table

  binds = [[nil, table]]
  binds << [nil, schema] if schema

  exec_query("      SELECT COUNT(*)\n      FROM pg_class c\n      LEFT JOIN pg_namespace n ON n.oid = c.relnamespace\n      WHERE c.relkind in ('v','r')\n      AND c.relname = '\#{table.gsub(/(^\"|\"$)/,'')}'\n      AND n.nspname = \#{schema ? \"'\#{schema}'\" : 'ANY (current_schemas(false))'}\n  SQL\nend\n", 'SCHEMA').rows.first[0].to_i > 0

#tables(name = nil) ⇒ Object

Returns the list of all tables in the schema search path or a specified schema.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 808

def tables(name = nil)
  query("    SELECT schemaname, tablename\n    FROM pg_tables\n    WHERE schemaname = ANY (current_schemas(false))\n  SQL\nend\n", 'SCHEMA').map { |row| "#{row[0]}.#{row[1]}" }

#type_cast(value, column) ⇒ Object 



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 481

def type_cast(value, column)
  return super unless column

  case value
  when String
    return super unless 'bytea' == column.sql_type
    { :value => value, :format => 1 }
  else
    super
  end
end

#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object

Maps logical Rails types to Redshift-specific data types.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 1060

def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  case type.to_s
  when 'binary'
    # Redshift doesn't support limits on binary (bytea) columns.
    # The hard limit is 1Gb, because of a 32-bit size field, and TOAST.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "No binary type has byte size #{limit}.")
    end
  when 'integer'
    return 'integer' unless limit

    case limit
      when 1, 2; 'smallint'
      when 3, 4; 'integer'
      when 5..8; 'bigint'
      else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
    end
  else
    super
  end
end

#unescape_bytea(value) ⇒ Object

Unescapes bytea output from a database to the binary string it represents. NOTE: This is NOT an inverse of escape_bytea! This is only to be used

on escaped binary output from database drive.



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

def unescape_bytea(value)
  @connection.unescape_bytea(value) if value
end

#update_sql(sql, name = nil) ⇒ Object

Executes an UPDATE query and returns the number of affected tuples.



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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 721

def update_sql(sql, name = nil)
  super.cmd_tuples
end

#use_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/redshift_adapter.rb', line 756

def use_insert_returning?
  @use_insert_returning
end