Module: Switchman::ActiveRecord::PostgreSQLAdapter

Defined in:
lib/switchman/active_record/postgresql_adapter.rb

Instance Method Summary collapse

Instance Method Details

#add_index_options(_table_name, _column_name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 230

def add_index_options(_table_name, _column_name, **)
  index_name, index_type, index_columns, index_options, algorithm, using = super
  algorithm = nil if DatabaseServer.creating_new_shard && algorithm == "CONCURRENTLY"
  [index_name, index_type, index_columns, index_options, algorithm, using]
end

#columns ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 258

def columns(*)
  with_local_table_name(false) { super }
end

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

copy/paste; use quote_local_table_name



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 7

def create_database(name, options = {})
  options = { encoding: 'utf8' }.merge!(options.symbolize_keys)

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

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

#current_schemas ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 39

def current_schemas
  select_values("SELECT * FROM unnest(current_schemas(false))")
end

#drop_database(name) ⇒ Object

copy/paste; use quote_local_table_name



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 35

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

#extract_schema_qualified_name(string) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 43

def extract_schema_qualified_name(string)
  name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(string.to_s)
  if string && !name.schema
    name.instance_variable_set(:@schema, shard.name)
  end
  [name.schema, name.identifier]
end

#foreign_keys(table_name) ⇒ Object 



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

def foreign_keys(table_name)
  # mostly copy-pasted from AR - only change is to the nspname condition for qualified names support
  fk_info = select_all <<-SQL.strip_heredoc
    SELECT t2.oid::regclass::text AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confupdtype AS on_update, c.confdeltype AS on_delete
    FROM pg_constraint c
    JOIN pg_class t1 ON c.conrelid = t1.oid
    JOIN pg_class t2 ON c.confrelid = t2.oid
    JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
    JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
    JOIN pg_namespace t3 ON c.connamespace = t3.oid
    WHERE c.contype = 'f'
      AND t1.relname = #{quote(table_name)}
      AND t3.nspname = '#{shard.name}'
    ORDER BY c.conname
  SQL

  fk_info.map do |row|
    options = {
      column: row['column'],
      name: row['name'],
      primary_key: row['primary_key']
    }

    options[:on_delete] = extract_foreign_key_action(row['on_delete'])
    options[:on_update] = extract_foreign_key_action(row['on_update'])

    # strip the schema name from to_table if it matches
    to_table = row['to_table']
    to_table_qualified_name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(to_table)
    if to_table_qualified_name.schema == shard.name
      to_table = to_table_qualified_name.identifier
    end

    ::ActiveRecord::ConnectionAdapters::ForeignKeyDefinition.new(table_name, to_table, options)
  end
end

#index_name_exists?(table_name, index_name, _default = nil) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 142

def index_name_exists?(table_name, index_name, _default = nil)
  exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
      SELECT COUNT(*)
      FROM pg_class t
      INNER JOIN pg_index d ON t.oid = d.indrelid
      INNER JOIN pg_class i ON d.indexrelid = i.oid
      WHERE i.relkind = 'i'
        AND i.relname = '#{index_name}'
        AND t.relname = '#{table_name}'
        AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = '#{shard.name}' )
  SQL
end

#indexes(table_name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 96

def indexes(table_name)
  result = query(<<-SQL, 'SCHEMA')
    SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid
    FROM pg_class t
    INNER JOIN pg_index d ON t.oid = d.indrelid
    INNER JOIN pg_class i ON d.indexrelid = i.oid
    WHERE i.relkind = 'i'
      AND d.indisprimary = 'f'
      AND t.relname = '#{table_name}'
      AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = '#{shard.name}' )
    ORDER BY i.relname
  SQL


  result.map do |row|
    index_name = row[0]
    unique = row[1] == true || row[1] == 't'
    indkey = row[2].split(" ")
    inddef = row[3]
    oid = row[4]

    columns = Hash[query(<<-SQL, "SCHEMA")]
    SELECT a.attnum, a.attname
    FROM pg_attribute a
    WHERE a.attrelid = #{oid}
    AND a.attnum IN (#{indkey.join(",")})
    SQL

    column_names = columns.stringify_keys.values_at(*indkey).compact

    unless column_names.empty?
      # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
      desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
      orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
      where = inddef.scan(/WHERE (.+)$/).flatten[0]
      using = inddef.scan(/USING (.+?) /).flatten[0].to_sym

      if ::Rails.version >= "5.2"
        ::ActiveRecord::ConnectionAdapters::IndexDefinition.new(table_name, index_name, unique, column_names, orders: orders, where: where, using: using)
      else
        ::ActiveRecord::ConnectionAdapters::IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using)
      end
    end
  end.compact
end

#quote_local_table_name(name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 202

def quote_local_table_name(name)
  # postgres quotes tables and columns the same; just pass through
  # (differs from quote_table_name_with_shard below by no logic to
  # explicitly qualify the table)
  quote_column_name(name)
end

#quote_table_name(name) ⇒ Object 



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

def quote_table_name(name)
  return quote_local_table_name(name) if @use_local_table_name
  name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(name.to_s)
  if !name.schema
    name.instance_variable_set(:@schema, shard.name)
  end
  name.quoted
end

#quoted_scope(name = nil, type: nil) ⇒ Object

significant change: use the shard name if no explicit schema



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 52

def quoted_scope(name = nil, type: nil)
  schema, name = extract_schema_qualified_name(name)
  type = \
    case type
    when "BASE TABLE"
      "'r','p'"
    when "VIEW"
      "'v','m'"
    when "FOREIGN TABLE"
      "'f'"
    end
  scope = {}
  scope[:schema] = quote(schema || shard.name)
  scope[:name] = quote(name) if name
  scope[:type] = type if type
  scope
end

#rename_index(table_name, old_name, new_name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 252

def rename_index(table_name, old_name, new_name)
  validate_index_length!(table_name, new_name)

  execute "ALTER INDEX #{quote_table_name(old_name)} RENAME TO #{quote_local_table_name(new_name)}"
end

#rename_table(table_name, new_name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 236

def rename_table(table_name, new_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_local_table_name(new_name)}"
  pk, seq = pk_and_sequence_for(new_name)
  if pk
    idx = "#{table_name}_pkey"
    new_idx = "#{new_name}_pkey"
    execute "ALTER INDEX #{quote_table_name(idx)} RENAME TO #{quote_local_table_name(new_idx)}"
    if seq && seq.identifier == "#{table_name}_#{pk}_seq"
      new_seq = "#{new_name}_#{pk}_seq"
      execute "ALTER TABLE #{seq.quoted} RENAME TO #{quote_local_table_name(new_seq)}"
    end
  end
  rename_table_indexes(table_name, new_name)
end

#tables(name = nil) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 71

def tables(name = nil)
  query(<<-SQL, 'SCHEMA').map { |row| row[0] }
    SELECT tablename
    FROM pg_tables
    WHERE schemaname = '#{shard.name}'
  SQL
end

#view_exists?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 79

def view_exists?(name)
  name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(name.to_s)
  return false unless name.identifier
  if !name.schema
    name.instance_variable_set(:@schema, shard.name)
  end

  select_values(<<-SQL, 'SCHEMA').any?
    SELECT c.relname
    FROM pg_class c
    LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
    WHERE c.relkind IN ('v','m') -- (v)iew, (m)aterialized view
    AND c.relname = '#{name.identifier}'
    AND n.nspname = '#{shard.name}'
  SQL
end

#with_global_table_name(&block) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 218

def with_global_table_name(&block)
  with_local_table_name(false, &block)
end

#with_local_table_name(enable = true) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 222

def with_local_table_name(enable = true)
  old_value = @use_local_table_name
  @use_local_table_name = enable
  yield
ensure
  @use_local_table_name = old_value
end