Make postgresql faster on development (thanks to @tapajos).

1 files changed, 8 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 255da7d183..b1f2f93462 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -122,6 +122,14 @@ module ActiveRecord
         # Extracts the value from a PostgreSQL column default definition.
         def self.extract_value_from_default(default)
           case default
+            # This is a performance optimization for Ruby 1.9.2 in development.
+            # If the value is nil, we return nil straight away without checking
+            # the regular expressions. If we check each regular expression,
+            # Regexp#=== will call NilClass#to_str, which will trigger
+            # method_missing (defined by whiny nil in ActiveSupport) which
+            # makes this method very very slow.
+            when NilClass
+              nil
             # Numeric types
             when /\A\(?(-?\d+(\.\d*)?\)?)\z/
               $1