Cache database version in schema cache

  * The database version will get cached in the schema cache file during the
    schema cache dump. When the database version check happens, the version will
    be pulled from the schema cache and thus avoid querying the database for
    the version.
  * If the schema cache file doesn't exist, we'll query the database for the
    version and cache it on the schema cache object.
  * To facilitate this change, all connection adapters now implement
    #get_database_version and #database_version. #database_version returns the
    value from the schema cache.
  * To take advantage of the cached database version, the database version check
    will now happen after the schema cache is set on the connection in the
    connection pool.

1 files changed, 12 insertions, 12 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index ff23a525b9..8504438d2d 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -111,7 +111,7 @@ module ActiveRecord
       end
 
       def supports_expression_index?
-        sqlite_version >= "3.9.0"
+        database_version >= "3.9.0"
       end
 
       def requires_reloading?
@@ -135,7 +135,7 @@ module ActiveRecord
       end
 
       def supports_insert_on_conflict?
-        sqlite_version >= "3.24.0"
+        database_version >= "3.24.0"
       end
       alias supports_insert_on_duplicate_skip? supports_insert_on_conflict?
       alias supports_insert_on_duplicate_update? supports_insert_on_conflict?
@@ -397,6 +397,16 @@ module ActiveRecord
         sql
       end
 
+      def get_database_version # :nodoc:
+        SQLite3Adapter::Version.new(query_value("SELECT sqlite_version(*)"))
+      end
+
+      def check_version # :nodoc:
+        if database_version < "3.8.0"
+          raise "Your version of SQLite (#{database_version}) is too old. Active Record supports SQLite >= 3.8."
+        end
+      end
+
       private
         # See https://www.sqlite.org/limits.html,
         # the default value is 999 when not configured.
@@ -404,12 +414,6 @@ module ActiveRecord
           999
         end
 
-        def check_version
-          if sqlite_version < "3.8.0"
-            raise "Your version of SQLite (#{sqlite_version}) is too old. Active Record supports SQLite >= 3.8."
-          end
-        end
-
         def initialize_type_map(m = type_map)
           super
           register_class_with_limit m, %r(int)i, SQLite3Integer
@@ -527,10 +531,6 @@ module ActiveRecord
                      SELECT #{quoted_from_columns} FROM #{quote_table_name(from)}")
         end
 
-        def sqlite_version
-          @sqlite_version ||= SQLite3Adapter::Version.new(query_value("SELECT sqlite_version(*)"))
-        end
-
         def translate_exception(exception, message:, sql:, binds:)
           case exception.message
           # SQLite 3.8.2 returns a newly formatted error message: