Module: Switchman::ActiveRecord::PostgreSQLAdapter

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

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.prepended(klass) ⇒ Object 



5
6
7
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 5

def self.prepended(klass)
  klass::NATIVE_DATABASE_TYPES[:primary_key] = "bigserial primary key".freeze
end

Instance Method Details

#add_index_options(_table_name, _column_name, _options = {}) ⇒ Object 



211
212
213
214
215
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 211

def add_index_options(_table_name, _column_name, _options = {})
  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

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

copy/paste; use quote_local_table_name



11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 11

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 



43
44
45
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 43

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

#drop_database(name) ⇒ Object

copy/paste; use quote_local_table_name



39
40
41
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 39

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

#foreign_keys(table_name) ⇒ Object 



172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 172

def foreign_keys(table_name)
  schema = shard.name if use_qualified_names?

  # 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 = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
    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 use_qualified_names? && 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) 


142
143
144
145
146
147
148
149
150
151
152
153
154
155
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 142

def index_name_exists?(table_name, index_name, _default = nil)
  schema = shard.name if use_qualified_names?

  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 = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'} )
  SQL
end

#indexes(table_name) ⇒ Object 



98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 98

def indexes(table_name)
  schema = shard.name if use_qualified_names?

  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 = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'} )
    ORDER BY i.relname
  SQL


  result.map do |row|
    index_name = row[0]
    unique = 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

      ::ActiveRecord::ConnectionAdapters::IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using)
    end
  end.compact
end

#quote_local_table_name(name) ⇒ Object 



157
158
159
160
161
162
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 157

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

#quote_table_name(name) ⇒ Object 



164
165
166
167
168
169
170
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 164

def quote_table_name name
  name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(name.to_s)
  if !name.schema && use_qualified_names?
    name.instance_variable_set(:@schema, shard.name)
  end
  name.quoted
end

#tables(name = nil) ⇒ Object 



51
52
53
54
55
56
57
58
59
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 51

def tables(name = nil)
  schema = shard.name if use_qualified_names?

  query(<<-SQL, 'SCHEMA').map { |row| row[0] }
    SELECT tablename
    FROM pg_tables
    WHERE schemaname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
  SQL
end

#use_qualified_names? ⇒ Boolean

Returns:

  • (Boolean) 


47
48
49
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 47

def use_qualified_names?
  @config[:use_qualified_names]
end

#view_exists?(name) ⇒ Boolean

Returns:

  • (Boolean) 


81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
 
# File 'lib/switchman/active_record/postgresql_adapter.rb', line 81

def view_exists?(name)
  name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(name.to_s)
  return false unless name.identifier
  if !name.schema && use_qualified_names?
    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 = #{name.schema ? "'#{name.schema}'" : 'ANY (current_schemas(false))'}
  SQL
end