2.0.0-0

README.mkd

@@ -13,13 +13,12 @@ gem 'pg_tasks', '>= 1.1.0', '< 2.0.0'
 
 ### Rake Tasks
 
-The following rake tasks are available: 
+The following rake tasks are available:
 
 ```shell
-rake db:pg:data:dump FILE=...
-rake db:pg:data:restore FILE=...
 rake db:pg:structure_and_data:dump FILE=...
 rake db:pg:structure_and_data:restore FILE=...
+rake db:pg:data:restore FILE=...
 rake db:pg:terminate_connections
 rake db:pg:truncate_tables
 ```
@@ -31,15 +30,40 @@ The FILE environment variable is optional. There are defaults.
 ### Access from Ruby Code
 
 ```ruby
-PgTasks.data_dump(filename = nil)
-PgTasks.data_restore(filename = nil)
 PgTasks.structure_and_data_dump(filename = nil)
 PgTasks.structure_and_data_restore(filename = nil)
+PgTasks.data_restore(filename = nil)
 PgTasks.terminate_connections()
 PgTasks.truncate_tables()
 ```
 
-## Internals and Caveats 
+## Breaking Changes from Version 1.x to 2.x
+
+The task `db:pg:data:dump` and the corresponding command `PgTasks.data_dump`
+has been removed.
+
+The task `db:pg:data:restore` and the corresponding command
+`PgTasks.data_restore` operate now only on dumps also including the schema.
+
+The task `db:pg:data:restore` and the corresponding command
+`PgTasks.data_restore` do not disable triggers!
+
+
+### Motivation
+
+* The integrity of the data is now checked also when restoring data only.
+
+* Most use cases require now only one dump (`structure_and_data`) instead of
+    two. This translates in ½ the time to create dumps and ½ the space required
+    to store them.
+
+You might ask why it hasn't been this way from the start? The facilities
+PostgreSQL provides clashes a bit with how ActiveRecord works with respect the
+`schema_migrations` table and you have to perform "a bit of a dance" to
+make it work this way.
+
+
+## Internals and Caveats
 
 This library uses and extends `ActiveRecord::Tasks::DatabaseTasks` as well as
 `ActiveRecord::Tasks::PostgreSQLDatabaseTasks`.
@@ -52,13 +76,9 @@ Restoring a complete database doesn't play well if there are open connections.
 Restore is carried out in a single transaction add will abort immediately if
 there is a problem.
 
-`data_dump` might warn you about circular dependencies. Never mind, `restore`
-disables the triggers temporarily. The role for restore requieres permissions
-to disable triggers temporarily.
-
-`data_dump` as well as `truncate_tables` leaves the `schema_migrations` table
+`data_restore` as well as `truncate_tables` leaves the `schema_migrations` table
 alone. This is the desired behavior for a library designed to interact with
 *ruby on rails* respectively *active record*.
 
 Calling `PgTasks.terminate_connections()` will also terminate the current
-connection. 
+connection.

lib/pg_tasks.rb

@@ -16,7 +16,7 @@ module PgTasks
   DEFAULT_BINARY_STRUCTURE_AND_DATA_FILE_NAME = 'structure_and_data.pgbin'
 
   class << self
-    %w(data_dump data_restore).each do |method_name|
+    %w(data_restore).each do |method_name|
       define_method method_name do |filename = nil|
         ActiveRecord::Tasks::DatabaseTasks \
           .perform_pg_db_task_for_config_and_filename \
@@ -70,30 +70,32 @@ def filename_or_default_binary_structure_and_data_file(filename)
 module ActiveRecord
   module Tasks
     class PostgreSQLDatabaseTasks
-      def data_dump(filename)
-        set_psql_env
-        command = 'pg_dump -F c -a -T schema_migrations -x -O -f ' \
-          "#{Shellwords.escape(filename.to_s)} " \
-          "#{Shellwords.escape(configuration['database'])}"
-        unless Kernel.system(command)
-          raise 'Error during data_dump'
-        else
-          $stdout.puts "The data of '#{configuration['database']} " \
-            "has been dumped to '#{filename}'"
-        end
-      end
 
       def data_restore(filename)
-        set_psql_env
-        command = 'pg_restore --disable-triggers --exit-on-error ' \
-          '--single-transaction -a -x -O ' \
-          "-d #{Shellwords.escape(configuration['database'])} " \
-          "#{Shellwords.escape(filename.to_s)}"
-        unless Kernel.system(command)
-          raise 'Error during data_restore '
-        else
-          $stdout.puts "Data from '#{filename}' has been restored to \
+        shell_filename= Shellwords.escape filename.to_s
+        list_cmd = "pg_restore -l #{shell_filename}"
+        pg_list = `#{list_cmd}`
+        raise "Command #{list_cmd} failed " if $?.exitstatus != 0
+        restore_list = pg_list.split(/\n/) \
+          .reject{|l| l =~ /TABLE DATA .* schema_migrations/}.join("\n")
+        begin
+          restore_list_file = Tempfile.new 'pg_restore_list'
+          restore_list_file.write restore_list
+
+          set_psql_env
+          command = 'pg_restore --data-only --exit-on-error ' \
+            ' --single-transaction --no-privileges --no-owner ' \
+            " -d #{Shellwords.escape(configuration['database'])} " \
+            " #{shell_filename }"
+          unless Kernel.system(command)
+            raise 'Error during data_restore '
+          else
+            $stdout.puts "Data from '#{filename}' has been restored to \
                         '#{configuration['database']}'"
+          end
+        ensure
+          restore_list_file.close
+          restore_list_file.unlink
         end
       end
 

lib/pg_tasks/version.rb

@@ -7,5 +7,5 @@
 #++
 
 module PgTasks
-  VERSION = '1.3.3'
+  VERSION = '2.0.0-0'
 end