diff options
Diffstat (limited to 'railties')
| -rw-r--r-- | railties/CHANGELOG.md | 2 | ||||
| -rw-r--r-- | railties/guides/source/active_record_querying.textile | 36 | ||||
| -rw-r--r-- | railties/guides/source/active_support_core_extensions.textile | 2 | ||||
| -rw-r--r-- | railties/test/generators/app_generator_test.rb | 6 |
4 files changed, 41 insertions, 5 deletions
diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md index 64abff6cb3..2841996b56 100644 --- a/railties/CHANGELOG.md +++ b/railties/CHANGELOG.md @@ -1,7 +1,7 @@ ## Rails 3.2.0 (unreleased) ## * New applications get a flag - `config.active_record.auto_explain_threshold_in_seconds` in the evironments + `config.active_record.auto_explain_threshold_in_seconds` in the environments configuration files. With a value of 0.5 in development.rb, and commented out in production.rb. No mention in test.rb. *fxn* diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile index 352f23dc01..0cbabd71a1 100644 --- a/railties/guides/source/active_record_querying.textile +++ b/railties/guides/source/active_record_querying.textile @@ -1369,6 +1369,42 @@ EXPLAIN for: SELECT `posts`.* FROM `posts` WHERE `posts`.`user_id` IN (1) under MySQL. +h4. Automatic EXPLAIN + +Active Record is able to run EXPLAIN automatically on slow queries and log its +output. This feature is controlled by the configuration parameter + +<ruby> +config.active_record.auto_explain_threshold_in_seconds +</ruby> + +If set to a number, any query exceeding those many seconds will have its EXPLAIN +automatically triggered and logged. In the case of relations, the threshold is +compared to the total time needed to fetch records. So, a relation is seen as a +unit of work, no matter whether the implementation of eager loading involves +several queries under the hood. + +A threshold of +nil+ disables automatic EXPLAINs. + +The default threshold in development mode is 0.5 seconds, and +nil+ in test and +production modes. + +h5. Disabling Automatic EXPLAIN + +Automatic EXPLAIN can be selectively silenced with +ActiveRecord::Base.silence_auto_explain+: + +<ruby> +ActiveRecord::Base.silence_auto_explain do + # no automatic EXPLAIN is triggered here +end +</ruby> + +That may be useful for queries you know are slow but fine, like a heavyweight +report of an admin interface. + +As its name suggests, +silence_auto_explain+ only silences automatic EXPLAINs. +Explicit calls to +ActiveRecord::Relation#explain+ run. + h4. Interpreting EXPLAIN Interpretation of the output of EXPLAIN is beyond the scope of this guide. The diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile index 76d757f6a7..6646e9cd05 100644 --- a/railties/guides/source/active_support_core_extensions.textile +++ b/railties/guides/source/active_support_core_extensions.textile @@ -2055,7 +2055,7 @@ NOTE: Defined in +active_support/core_ext/enumerable.rb+. h4. +pluck+ -Plucks the value of the passed method for each element and returns the result as an array +The +pluck+ method collects the value of the passed method for each element and returns the result as an array. <ruby> people.pluck(:name) # => [ "David Heinemeier Hansson", "Jamie Heinemeier Hansson" ] diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb index 41bb4d8b20..baa80419a6 100644 --- a/railties/test/generators/app_generator_test.rb +++ b/railties/test/generators/app_generator_test.rb @@ -329,8 +329,8 @@ class AppGeneratorTest < Rails::Generators::TestCase def test_generated_environments_file_for_sanitizer run_generator [destination_root, "--skip-active-record"] - ["config/environments/development.rb", "config/environments/test.rb"].each do |env_file| - assert_file env_file do |file| + %w(development test).each do |env| + assert_file "config/environments/#{env}.rb" do |file| assert_no_match(/config.active_record.mass_assignment_sanitizer = :strict/, file) end end @@ -338,7 +338,7 @@ class AppGeneratorTest < Rails::Generators::TestCase def test_generated_environments_file_for_auto_explain run_generator [destination_root, "--skip-active-record"] - %w(development test production).each do |env| + %w(development production).each do |env| assert_file "config/environments/#{env}.rb" do |file| assert_no_match %r(auto_explain_threshold_in_seconds), file end |