diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb')
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb | 284 |
1 files changed, 212 insertions, 72 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb index 5402918b1d..d2361b5378 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb @@ -7,9 +7,9 @@ gem 'pg', '~> 0.11' require 'pg' module ActiveRecord - class Base + module ConnectionHandling # Establishes a connection to the database that's used by all Active Record objects - def self.postgresql_connection(config) # :nodoc: + def postgresql_connection(config) # :nodoc: config = config.symbolize_keys host = config[:host] port = config[:port] || 5432 @@ -49,6 +49,42 @@ module ActiveRecord super end end + + def cast_hstore(object) + if Hash === object + object.map { |k,v| + "#{escape_hstore(k)}=>#{escape_hstore(v)}" + }.join ', ' + else + kvs = object.scan(/(?<!\\)".*?(?<!\\)"/).map { |o| + unescape_hstore(o[1...-1]) + } + Hash[kvs.each_slice(2).to_a] + end + end + + private + HSTORE_ESCAPE = { + ' ' => '\\ ', + '\\' => '\\\\', + '"' => '\\"', + '=' => '\\=', + } + HSTORE_ESCAPE_RE = Regexp.union(HSTORE_ESCAPE.keys) + HSTORE_UNESCAPE = HSTORE_ESCAPE.invert + HSTORE_UNESCAPE_RE = Regexp.union(HSTORE_UNESCAPE.keys) + + def unescape_hstore(value) + value.gsub(HSTORE_UNESCAPE_RE) do |match| + HSTORE_UNESCAPE[match] + end + end + + def escape_hstore(value) + value.gsub(HSTORE_ESCAPE_RE) do |match| + HSTORE_ESCAPE[match] + end + end end # :startdoc: @@ -79,53 +115,55 @@ module ActiveRecord # Maps PostgreSQL-specific data types to logical Rails types. def simplified_type(field_type) case field_type - # Numeric and monetary types - when /^(?:real|double precision)$/ - :float - # Monetary types - when 'money' - :decimal - # Character types - when /^(?:character varying|bpchar)(?:\(\d+\))?$/ - :string - # Binary data types - when 'bytea' - :binary - # Date/time types - when /^timestamp with(?:out)? time zone$/ - :datetime - when 'interval' - :string - # Geometric types - when /^(?:point|line|lseg|box|"?path"?|polygon|circle)$/ - :string - # Network address types - when /^(?:cidr|inet|macaddr)$/ - :string - # Bit strings - when /^bit(?: varying)?(?:\(\d+\))?$/ - :string - # XML type - when 'xml' - :xml - # tsvector type - when 'tsvector' - :tsvector - # Arrays - when /^\D+\[\]$/ - :string - # Object identifier types - when 'oid' - :integer - # UUID type - when 'uuid' - :string - # Small and big integer types - when /^(?:small|big)int$/ - :integer - # Pass through all types that are not specific to PostgreSQL. - else - super + # Numeric and monetary types + when /^(?:real|double precision)$/ + :float + # Monetary types + when 'money' + :decimal + when 'hstore' + :hstore + # Character types + when /^(?:character varying|bpchar)(?:\(\d+\))?$/ + :string + # Binary data types + when 'bytea' + :binary + # Date/time types + when /^timestamp with(?:out)? time zone$/ + :datetime + when 'interval' + :string + # Geometric types + when /^(?:point|line|lseg|box|"?path"?|polygon|circle)$/ + :string + # Network address types + when /^(?:cidr|inet|macaddr)$/ + :string + # Bit strings + when /^bit(?: varying)?(?:\(\d+\))?$/ + :string + # XML type + when 'xml' + :xml + # tsvector type + when 'tsvector' + :tsvector + # Arrays + when /^\D+\[\]$/ + :string + # Object identifier types + when 'oid' + :integer + # UUID type + when 'uuid' + :string + # Small and big integer types + when /^(?:small|big)int$/ + :integer + # Pass through all types that are not specific to PostgreSQL. + else + super end end @@ -215,6 +253,10 @@ module ActiveRecord options = args.extract_options! column(args[0], 'tsvector', options) end + + def hstore(name, options = {}) + column(name, 'hstore', options) + end end ADAPTER_NAME = 'PostgreSQL' @@ -247,6 +289,10 @@ module ActiveRecord true end + def supports_index_sort_order? + true + end + class StatementPool < ConnectionAdapters::StatementPool def initialize(connection, max) super @@ -278,13 +324,24 @@ module ActiveRecord cache.clear end + def delete(sql_key) + dealloc cache[sql_key] + cache.delete sql_key + end + private def cache @cache[$$] end def dealloc(key) - @connection.query "DEALLOCATE #{key}" + @connection.query "DEALLOCATE #{key}" if connection_active? + end + + def connection_active? + @connection.status == PGconn::CONNECTION_OK + rescue PGError + false end end @@ -292,6 +349,7 @@ module ActiveRecord def initialize(connection, logger, connection_parameters, config) super(connection, logger) @connection_parameters, @config = connection_parameters, config + @visitor = Arel::Visitors::PostgreSQL.new self # @local_tz is initialized as nil to avoid warnings when connect tries to use it @local_tz = nil @@ -308,10 +366,6 @@ module ActiveRecord @local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"] end - def self.visitor_for(pool) # :nodoc: - Arel::Visitors::PostgreSQL.new(pool) - end - # Clears the prepared statements cache. def clear_cache! @statements.clear @@ -378,6 +432,11 @@ module ActiveRecord true end + # Returns true. + def supports_explain? + true + end + # Returns the configured supported identifier length supported by PostgreSQL def table_alias_length @table_alias_length ||= query('SHOW max_identifier_length')[0][0].to_i @@ -502,6 +561,48 @@ module ActiveRecord # DATABASE STATEMENTS ====================================== + def explain(arel, binds = []) + sql = "EXPLAIN #{to_sql(arel)}" + ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds)) + end + + class ExplainPrettyPrinter # :nodoc: + # Pretty prints the result of a EXPLAIN in a way that resembles the output of the + # PostgreSQL shell: + # + # QUERY PLAN + # ------------------------------------------------------------------------------ + # Nested Loop Left Join (cost=0.00..37.24 rows=8 width=0) + # Join Filter: (posts.user_id = users.id) + # -> Index Scan using users_pkey on users (cost=0.00..8.27 rows=1 width=4) + # Index Cond: (id = 1) + # -> Seq Scan on posts (cost=0.00..28.88 rows=8 width=4) + # Filter: (posts.user_id = 1) + # (6 rows) + # + def pp(result) + header = result.columns.first + lines = result.rows.map(&:first) + + # We add 2 because there's one char of padding at both sides, note + # the extra hyphens in the example above. + width = [header, *lines].map(&:length).max + 2 + + pp = [] + + pp << header.center(width).rstrip + pp << '-' * width + + pp += lines.map {|line| " #{line}"} + + nrows = result.rows.length + rows_label = nrows == 1 ? 'row' : 'rows' + pp << "(#{nrows} #{rows_label})" + + pp.join("\n") + "\n" + end + end + # Executes a SELECT query and returns an array of rows. Each row is an # array of field values. def select_rows(sql, name = nil) @@ -743,16 +844,15 @@ module ActiveRecord # Returns an array of indexes for the given table. def indexes(table_name, name = nil) - schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',') result = query(<<-SQL, name) - SELECT distinct i.relname, d.indisunique, d.indkey, t.oid + 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 IN (#{schemas}) ) + AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) ) ORDER BY i.relname SQL @@ -761,7 +861,8 @@ module ActiveRecord index_name = row[0] unique = row[1] == 't' indkey = row[2].split(" ") - oid = row[3] + inddef = row[3] + oid = row[4] columns = Hash[query(<<-SQL, "Columns for index #{row[0]} on #{table_name}")] SELECT a.attnum, a.attname @@ -771,7 +872,12 @@ module ActiveRecord SQL column_names = columns.values_at(*indkey).compact - column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names) + + # 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]}] : {} + + column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders) end.compact end @@ -815,7 +921,7 @@ module ActiveRecord # Returns the active schema search path. def schema_search_path - @schema_search_path ||= query('SHOW search_path')[0][0] + @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0] end # Returns the current client message level. @@ -911,12 +1017,14 @@ module ActiveRecord # Example: # rename_table('octopuses', 'octopi') def rename_table(name, new_name) + clear_cache! execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}" end # Adds a new column to the named table. # See TableDefinition#column for details of the options you can use. 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) @@ -925,6 +1033,7 @@ module ActiveRecord # Changes the column of a table. 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])}" @@ -935,10 +1044,12 @@ module ActiveRecord # Changes the default value of a table column. 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 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 @@ -947,6 +1058,7 @@ module ActiveRecord # Renames a column in a table. 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 @@ -1030,26 +1142,54 @@ module ActiveRecord end private + FEATURE_NOT_SUPPORTED = "0A000" # :nodoc: + def exec_no_cache(sql, binds) @connection.async_exec(sql) end def exec_cache(sql, binds) - unless @statements.key? sql - nextkey = @statements.next_key - @connection.prepare nextkey, sql - @statements[sql] = nextkey + begin + stmt_key = prepare_statement sql + + # Clear the queue + @connection.get_last_result + @connection.send_query_prepared(stmt_key, binds.map { |col, val| + type_cast(val, col) + }) + @connection.block + @connection.get_last_result + rescue PGError => e + # Get the PG code for the failure. Annoyingly, the code for + # prepared statements whose return value may have changed is + # FEATURE_NOT_SUPPORTED. Check here for more details: + # http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573 + code = e.result.result_error_field(PGresult::PG_DIAG_SQLSTATE) + if FEATURE_NOT_SUPPORTED == code + @statements.delete sql_key(sql) + retry + else + raise e + end end + end - key = @statements[sql] + # Returns the statement identifier for the client side cache + # of statements + def sql_key(sql) + "#{schema_search_path}-#{sql}" + end - # Clear the queue - @connection.get_last_result - @connection.send_query_prepared(key, binds.map { |col, val| - type_cast(val, col) - }) - @connection.block - @connection.get_last_result + # Prepare the statement if it hasn't been prepared, return + # the statement key. + def prepare_statement(sql) + sql_key = sql_key(sql) + unless @statements.key? sql_key + nextkey = @statements.next_key + @connection.prepare nextkey, sql + @statements[sql_key] = nextkey + end + @statements[sql_key] end # The internal PostgreSQL identifier of the money data type. |