Updates readme

[ci skip]

README.md

@@ -187,13 +187,10 @@ predicate for the `&&` operator.
 
 ```ruby
 user_arel = User.arel_table
-query = user_arel.where(user_arel[:tags].array_overlap(['one','two']))
-                 .project(Arel.sql('*'))
-query.to_sql
-# => SELECT \"users\".* FROM \"users\" WHERE \"users\".\"tags\" && '{one,two}'
 
 # Execute the query
-User.find_by_sql(query.to_sql)
+User.where(user_arel[:tags].array_overlap(['one','two']))
+# => SELECT \"users\".* FROM \"users\" WHERE \"users\".\"tags\" && '{one,two}'
 ```
 
 #### ANY or ALL functions
@@ -223,13 +220,10 @@ user_arel = User.arel_table
 
 any_tags_function = Arel::Nodes::NamedFunction.new('ANY', [user_arel[:tags]])
 predicate = Arel::Nodes::Equality.new('test', any_tags_function)
-query = user_arel.where(predicate).project(Arel.sql('*'))
-
-query.to_sql
-#=> SELECT \"users\".* FROM \"users\" WHERE 'test' = ANY(\"users\".\"tags\")
 
 # Execute the query
-User.find_by_sql(query.to_sql)
+User.where(predicate)
+#=> SELECT \"users\".* FROM \"users\" WHERE 'test' = ANY(\"users\".\"tags\")
 ```
 
 The ALL version of this same predicate can be generated by swap `'ANY'`
@@ -256,24 +250,22 @@ predicate for the `<<` operator.
 
 ```ruby
 user_arel = User.arel_table
-query = user_arel.where(user_arel[:ip_address].contained_witin('127.0.0.1/24'))
-                 .project(Arel.sql('*'))
-
-query.to_sql
-# => SELECT \"users\".* FROM \"users\" WHERE \"users\".\"ip_address\" << '127.0.0.1/24'
 
 # Execute the query
-User.find_by_sql(query.to_sql)
+User.where(user_arel[:ip_address].contained_witin('127.0.0.1/24'))
+# => SELECT \"users\".* FROM \"users\" WHERE \"users\".\"ip_address\" << '127.0.0.1/24'
 ```
 
 ## Indexes
 
 ### Index types
 
-Postgres\_ext allows you to specify an index type at index creation.
+Postgres\_ext allows you to specify index type and index operator
+class at index creation.
 
 ```ruby
 add_index :table_name, :column, :index_type => :gin
+add_index :table_name, :column, :index_type => :gin, :index_opclass => :gin_trgm_ops
 ```
 
 ### Where clauses