Module: ActiveRecord::PGExtensions::PostgreSQLAdapter

Defined in:
lib/active_record/pg_extensions/extension.rb,
lib/active_record/pg_extensions/postgresql_adapter.rb

Overview

Contains general additions to the PostgreSQLAdapter

Defined Under Namespace

Classes: Extension

Constant Summary collapse

TIMEOUTS = 
%i[lock_timeout statement_timeout idle_in_transaction_session_timeout].freeze

Instance Method Summary collapse

Instance Method Details

#add_check_constraint(table_name, expression, name:, validate: true) ⇒ Object 



278
279
280
281
282
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 278

def add_check_constraint(table_name, expression, name:, validate: true)
  sql = +"ALTER TABLE #{quote_table_name(table_name)} ADD CONSTRAINT #{quote_column_name(name)} CHECK (#{expression})" # rubocop:disable Layout/LineLength
  sql << " NOT VALID" unless validate
  execute(sql)
end

#add_schema_to_search_path(schema) ⇒ Object

temporarily adds schema to the search_path (i.e. so you can use an extension that won't work without being on the search path, such as postgis)



109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 109

def add_schema_to_search_path(schema)
  if schema_search_path.split(",").include?(schema)
    yield
  else
    old_search_path = schema_search_path
    manual_rollback = false
    transaction(requires_new: true) do
      self.schema_search_path += ",#{schema}"
      yield
      self.schema_search_path = old_search_path
    rescue ActiveRecord::StatementInvalid, ActiveRecord::Rollback => e
      # the transaction rolling back will revert the search path change;
      # we don't need to do another query to set it
      @schema_search_path = old_search_path
      manual_rollback = e if e.is_a?(ActiveRecord::Rollback)
      raise
    end
    # the transaction call will swallow ActiveRecord::Rollback,
    # but we want it this method to be transparent
    raise manual_rollback if manual_rollback
  end
end

#alter_extension(extension, schema: nil, version: nil) ⇒ Object

see www.postgresql.org/docs/current/sql-alterextension.html



55
56
57
58
59
60
61
62
63
64
65
66
67
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 55

def alter_extension(extension, schema: nil, version: nil)
  if schema && version
    raise ArgumentError, "Cannot change schema and upgrade to a particular version in a single statement"
  end

  sql = +"ALTER EXTENSION #{extension}"
  sql << " UPDATE" if version
  sql << " TO #{quote(version)}" if version && version != true
  sql << " SET SCHEMA #{schema}" if schema
  execute(sql)
  reload_type_map
  @extensions&.delete(extension.to_s)
end

#create_extension(extension, if_not_exists: false, schema: nil, version: nil, cascade: false) ⇒ Object

see www.postgresql.org/docs/current/sql-createextension.html



42
43
44
45
46
47
48
49
50
51
52
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 42

def create_extension(extension, if_not_exists: false, schema: nil, version: nil, cascade: false)
  sql = +"CREATE EXTENSION "
  sql <<= "IF NOT EXISTS " if if_not_exists
  sql << extension.to_s
  sql << " SCHEMA #{schema}" if schema
  sql << " VERSION #{quote(version)}" if version
  sql << " CASCADE" if cascade
  execute(sql)
  reload_type_map
  @extensions&.delete(extension.to_s)
end

#current_wal_flush_lsn ⇒ Object

see www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.33.5.5.2.2.2.1.1.1



189
190
191
192
193
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 189

def current_wal_flush_lsn
  return nil unless wal?

  select_value("SELECT #{pre_pg10_wal_function_name('pg_current_wal_flush_lsn')}()")
end

#current_wal_insert_lsn ⇒ Object

see www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.33.5.5.2.2.3.1.1.1



196
197
198
199
200
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 196

def current_wal_insert_lsn
  return nil unless wal?

  select_value("SELECT #{pre_pg10_wal_function_name('pg_current_wal_insert_lsn')}()")
end

#current_wal_lsn ⇒ Object

see www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.33.5.5.2.2.4.1.1.1



182
183
184
185
186
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 182

def current_wal_lsn
  return nil unless wal?

  select_value("SELECT #{pre_pg10_wal_function_name('pg_current_wal_lsn')}()")
end

#defer_constraints(*constraints) ⇒ Object

defers constraints, yields to the caller, and then resets back to immediate note that the reset back to immediate is not in an ensure block, since any error thrown would likely mean the transaction is rolled back, and setting constraint checking back to immediate would also fail



24
25
26
27
28
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 24

def defer_constraints(*constraints)
  set_constraints(:deferred, *constraints)
  yield
  set_constraints(:immediate, *constraints)
end

#drop_extension(*extensions, if_exists: false, cascade: false) ⇒ Object

see www.postgresql.org/docs/current/sql-dropextension.html

Raises:

  • (ArgumentError) 


70
71
72
73
74
75
76
77
78
79
80
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 70

def drop_extension(*extensions, if_exists: false, cascade: false)
  raise ArgumentError, "wrong number of arguments (given 0, expected 1+)" if extensions.empty?

  sql = +"DROP EXTENSION "
  sql << "IF EXISTS " if if_exists
  sql << extensions.join(", ")
  sql << " CASCADE" if cascade
  execute(sql)
  reload_type_map
  @extensions&.except!(*extensions.map(&:to_s))
end

#extension(extension) ⇒ Object

returns an Extension object for a particular extension



92
93
94
95
96
97
98
99
100
101
102
103
104
105
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 92

def extension(extension)
  @extensions ||= {}
  @extensions.fetch(extension.to_s) do
    rows = select_rows(<<~SQL, "SCHEMA")
      SELECT nspname, extversion
      FROM pg_extension
        INNER JOIN pg_namespace ON extnamespace=pg_namespace.oid
      WHERE extname=#{quote(extension)}
    SQL
    next nil if rows.empty?

    Extension.new(extension.to_s, rows[0][0], rows[0][1])
  end
end

#extension_available?(extension, version = nil) ⇒ Boolean

check if a particular extension can be installed

Returns:

  • (Boolean) 


83
84
85
86
87
88
89
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 83

def extension_available?(extension, version = nil)
  sql = +"SELECT 1 FROM "
  sql << (version ? "pg_available_extension_versions" : "pg_available_extensions")
  sql << " WHERE name=#{quote(extension)}"
  sql << " AND version=#{quote(version)}" if version
  select_value(sql).to_i == 1
end

#in_recovery? ⇒ Boolean

Returns:

  • (Boolean) 


235
236
237
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 235

def in_recovery?
  select_value("SELECT pg_is_in_recovery()")
end

#last_wal_receive_lsn ⇒ Object

www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.33.6.3.2.2.2.1.1.1



203
204
205
206
207
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 203

def last_wal_receive_lsn
  return nil unless wal?

  select_value("SELECT #{pre_pg10_wal_function_name('pg_last_wal_receive_lsn')}()")
end

#last_wal_replay_lsn ⇒ Object

see www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.33.6.3.2.2.3.1.1.1



210
211
212
213
214
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 210

def last_wal_replay_lsn
  return nil unless wal?

  select_value("SELECT #{pre_pg10_wal_function_name('pg_last_wal_replay_lsn')}()")
end

#remove_check_constraint(table_name, name:) ⇒ Object 



284
285
286
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 284

def remove_check_constraint(table_name, name:)
  execute("ALTER TABLE #{quote_table_name(table_name)} DROP CONSTRAINT #{quote_column_name(name)}")
end

#reset(configuration_parameter) ⇒ Object 



244
245
246
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 244

def reset(configuration_parameter)
  execute("RESET #{configuration_parameter}")
end

#set(configuration_parameter, value, local: false) ⇒ Object 



239
240
241
242
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 239

def set(configuration_parameter, value, local: false)
  value = value.nil? ? "DEFAULT" : quote(value)
  execute("SET#{' LOCAL' if local} #{configuration_parameter} TO #{value}")
end

#set_constraints(deferred, *constraints) ⇒ Object

set constraint check timing for the current transaction see www.postgresql.org/docs/current/sql-set-constraints.html

Raises:

  • (ArgumentError) 


11
12
13
14
15
16
17
18
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 11

def set_constraints(deferred, *constraints)
  raise ArgumentError, "deferred must be :deferred or :immediate" unless %w[deferred
                                                                            immediate].include?(deferred.to_s)

  constraints = constraints.map { |c| quote_table_name(c) }.join(", ")
  constraints = "ALL" if constraints.empty?
  execute("SET CONSTRAINTS #{constraints} #{deferred.to_s.upcase}")
end

#set_replica_identity(table, identity = :default) ⇒ Object

see www.postgresql.org/docs/current/sql-altertable.html#SQL-CREATETABLE-REPLICA-IDENTITY



31
32
33
34
35
36
37
38
39
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 31

def set_replica_identity(table, identity = :default)
  identity_clause = case identity
                    when :default, :full, :nothing
                      identity.to_s.upcase
                    else
                      "USING INDEX #{quote_column_name(identity)}"
                    end
  execute("ALTER TABLE #{quote_table_name(table)} REPLICA IDENTITY #{identity_clause}")
end

#vacuum(*table_and_columns, full: false, freeze: false, verbose: false, analyze: false, disable_page_skipping: false, skip_locked: false, index_cleanup: false, truncate: false, parallel: nil) ⇒ Object

see www.postgresql.org/docs/current/sql-vacuum.html



133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 133

def vacuum(*table_and_columns,
           full: false,
           freeze: false,
           verbose: false,
           analyze: false,
           disable_page_skipping: false,
           skip_locked: false,
           index_cleanup: false,
           truncate: false,
           parallel: nil)
  if parallel && !(parallel.is_a?(Integer) && parallel.positive?)
    raise ArgumentError, "parallel must be a positive integer"
  end

  sql = +"VACUUM"
  sql << " FULL" if full
  sql << " FREEZE" if freeze
  sql << " VERBOSE" if verbose
  sql << " ANALYZE" if analyze
  sql << " DISABLE_PAGE_SKIPPING" if disable_page_skipping
  sql << " SKIP_LOCKED" if skip_locked
  sql << " INDEX_CLEANUP" if index_cleanup
  sql << " TRUNCATE" if truncate
  sql << " PARALLEL #{parallel}" if parallel
  sql << " " unless table_and_columns.empty?
  sql << table_and_columns.map do |table|
    if table.is_a?(Hash)
      raise ArgumentError, "columns may only be specified if a analyze is specified" unless analyze

      table.map do |table_name, columns|
        "#{quote_table_name(table_name)} (#{Array.wrap(columns).map { |c| quote_column_name(c) }.join(', ')})"
      end.join(", ")
    else
      quote_table_name(table)
    end
  end.join(", ")
  execute(sql)
end

#wal? ⇒ Boolean

Amazon Aurora doesn't have a WAL

Returns:

  • (Boolean) 


173
174
175
176
177
178
179
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 173

def wal?
  unless instance_variable_defined?(:@has_wal)
    function_name = pre_pg10_wal_function_name("pg_current_wal_lsn")
    @has_wal = select_value("SELECT true FROM pg_proc WHERE proname='#{function_name}' LIMIT 1")
  end
  @has_wal
end

#wal_lsn_diff(lsn1 = :current, lsn2 = :last_replay) ⇒ Object

see www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.33.5.5.2.2.4.1.1.1 lsns can be literals, or :current, :current_flush, :current_insert, :last_receive, or :last_replay



218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 218

def wal_lsn_diff(lsn1 = :current, lsn2 = :last_replay)
  return nil unless wal?

  lsns = [lsn1, lsn2].map do |lsn|
    case lsn
    when :current then pre_pg10_wal_function_name("pg_current_wal_lsn()")
    when :current_flush then pre_pg10_wal_function_name("pg_current_flush_wal_lsn()")
    when :current_insert then pre_pg10_wal_function_name("pg_current_insert_wal_lsn()")
    when :last_receive then pre_pg10_wal_function_name("pg_last_wal_receive_lsn()")
    when :last_replay then pre_pg10_wal_function_name("pg_last_wal_replay_lsn()")
    else; quote(lsn)
    end
  end

  select_value("SELECT #{pre_pg10_wal_function_name('pg_wal_lsn_diff')}(#{lsns[0]}, #{lsns[1]})")
end

#with_statement_timeout(timeout = nil) ⇒ Object

@deprecated: manage the transaction yourself and set statement_timeout directly

otherwise, if you're already in a transaction, or you nest with_statement_timeout, the value will unexpectedly “stick” even after the block returns



268
269
270
271
272
273
274
275
 
# File 'lib/active_record/pg_extensions/postgresql_adapter.rb', line 268

def with_statement_timeout(timeout = nil)
  timeout = 30 if timeout.nil? || timeout == true

  transaction do
    self.statement_timeout = timeout
    yield
  end
end