PostgreSQL and SQLite, remove varchar limit. [Vladimir Sazhin & Toms Mikoss & Yves Senn]

There is no reason for the PG adapter to have a default limit of 255 on :string
columns. See this snippet from the PG docs:

    Tip: There is no performance difference among these three types, apart
    from increased storage space when using the blank-padded type, and a
    few extra CPU cycles to check the length when storing into a
    length-constrained column. While character(n) has performance
    advantages in some other database systems, there is no such advantage
    in PostgreSQL; in fact character(n) is usually the slowest of the
    three because of its additional storage costs. In most situations text
    or character varying should be used instead.

2 files changed, 2 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 9fe8e0497e..3510e4f3b0 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -209,7 +209,7 @@ module ActiveRecord
 
       NATIVE_DATABASE_TYPES = {
         primary_key: "serial primary key",
-        string:      { name: "character varying", limit: 255 },
+        string:      { name: "character varying" },
         text:        { name: "text" },
         integer:     { name: "integer" },
         float:       { name: "float" },
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 6e6a51dab8..cd1f7a16c6 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -63,7 +63,7 @@ module ActiveRecord
 
       NATIVE_DATABASE_TYPES = {
         primary_key:  'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL',
-        string:       { name: "varchar", limit: 255 },
+        string:       { name: "varchar" },
         text:         { name: "text" },
         integer:      { name: "integer" },
         float:        { name: "float" },