add "IMPROVING PERFORMANCE" section to Cookbook

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Manual / Cookbook.pod

diff --git a/lib/DBIx/Class/Manual/Cookbook.pod b/lib/DBIx/Class/Manual/Cookbook.pod
index 5524c18..590e439 100644 (file)
--- a/lib/DBIx/Class/Manual/Cookbook.pod
+++ b/lib/DBIx/Class/Manual/Cookbook.pod
@@ -367,8 +367,8 @@ That creates the following SQL:
 
 =head2 Predefined searches
 
-You can write your own L<DBIx::Class::ResultSet> class by inheriting from it
-and defining often used searches as methods:
+You can define frequently used searches as methods by subclassing
+L<DBIx::Class::ResultSet>:
 
   package My::DBIC::ResultSet::CD;
   use strict;
@@ -415,6 +415,12 @@ supports indexes on expressions - including return values of functions - and
 you create an index on the return value of the function in question.) However,
 it can be accomplished with C<DBIx::Class> when necessary.
 
+Your approach for doing so will depend on whether you have turned
+quoting on via the C<quote_char> and C<name_sep> attributes. If you
+explicitly defined C<quote_char> and C<name_sep> in your
+C<connect_info> (see L<DBIx::Class::Storage::DBI/"connect_info">) then
+you are using quoting, otherwise not.
+
 If you do not have quoting on, simply include the function in your search
 specification as you would any column:
 
@@ -2078,6 +2084,47 @@ You could then create average, high and low execution times for an SQL
 statement and dig down to see if certain parameters cause aberrant behavior.
 You might want to check out L<DBIx::Class::QueryLog> as well.
 
+=head1 IMPROVING PERFORMANCE
+
+=over
+
+=item *
+
+Install L<Class::XSAccessor> to speed up L<Class::Accessor::Grouped>.
+
+=item *
+
+On Perl 5.8 install L<Class::C3::XS>.
+
+=item *
+
+L<prefetch|DBIx::Class::ResultSet/prefetch> relationships, where possible. See
+L</Using joins and prefetch>.
+
+=item *
+
+Use L<populate|DBIx::Class::ResultSet/populate> in void context to insert data
+when you don't need the resulting L<DBIx::Class::Row> objects, if possible, but
+see the caveats.
+
+When inserting many rows, for best results, populate a large number of rows at a
+time, but not so large that the table is locked for an unacceptably long time.
+
+If using L<create|DBIx::Class::ResultSet/create> instead, use a transaction and
+commit every C<X> rows; where C<X> gives you the best performance without
+locking the table for too long. 
+
+=item *
+
+When selecting many rows, if you don't need full-blown L<DBIx::Class::Row>
+objects, consider using L<DBIx::Class::ResultClass::HashRefInflator>.
+
+=item *
+
+See also L</STARTUP SPEED> and L</MEMORY USAGE> in this document.
+
+=back
+
 =head1 STARTUP SPEED
 
 L<DBIx::Class|DBIx::Class> programs can have a significant startup delay