NAME

DBIx::Class::Helper::ResultSet::Explain - Get query plan for a ResultSet

SYNOPSIS

This module mostly makes sense to be used without setting as a component:

 ues Devel::Dwarn;
 Dwarn DBIx::Class::ResultSet::Explain::explain($rs)

But as usual, if you prefer to use it as a component here's how:

 package MyApp::Schema::ResultSet::Foo;

 __PACKAGE__->load_components(qw{Helper::ResultSet::Explain});

 ...

 1;

And then in a script or something:

 use Devel::Dwarn;
 Dwarn $rs->explain;

DESCRIPTION

This is just a handy little tool that gives you the query plan for a given ResultSet. The output is in no way normalized, so just treat it as a debug tool or something. The only supported DB's are those listed below. Have fun!

See "NOTE" in DBIx::Class::Helper::ResultSet for a nice way to apply it to your entire schema.

EXAMPLE OUTPUT FROM SUPPORTED DB's

SQlite

 [
   [
     0,
     "Init",
     0,
     11,
     0,
     "",
     "00",
     undef
   ],
   [
     1,
     "OpenRead",
     0,
     3,
     0,
     4,
     "00",
     undef
   ],
   [
     2,
     "Rewind",
     0,
     9,
     0,
     "",
     "00",
     undef
   ],
   [
     3,
     "Rowid",
     0,
     1,
     0,
     "",
     "00",
     undef
   ],
   [
     4,
     "Column",
     0,
     1,
     2,
     "",
     "00",
     undef
   ],
   [
     5,
     "Column",
     0,
     2,
     3,
     "",
     "00",
     undef
   ],
   [
     6,
     "Column",
     0,
     3,
     4,
     "",
     "00",
     undef
   ],
   [
     7,
     "ResultRow",
     1,
     4,
     0,
     "",
     "00",
     undef
   ],
   [
     8,
     "Next",
     0,
     3,
     0,
     "",
     "01",
     undef
   ],
   [
     9,
     "Close",
     0,
     0,
     0,
     "",
     "00",
     undef
   ],
   [
     10,
     "Halt",
     0,
     0,
     0,
     "",
     "00",
     undef
   ],
   [
     11,
     "Transaction",
     0,
     0,
     14,
     0,
     "01",
     undef
   ],
   [
     12,
     "TableLock",
     0,
     3,
     0,
     "Gnarly",
     "00",
     undef
   ],
   [
     13,
     "Goto",
     0,
     1,
     0,
     "",
     "00",
     undef
   ]
 ]

Pg

 [
   [
     "Seq Scan on \"Gnarly\" me  (cost=0.00..16.20 rows=620 width=100) (actual time=0.002..0.002 rows=0 loops=1)"
   ],
   [
     "Total runtime: 0.022 ms"
   ]
 ]

mysql

 [
   [
     1,
     "SIMPLE",
     "me",
     "ALL",
     undef,
     undef,
     undef,
     undef,
     1,
     "100.00",
     ""
   ]
 ]

AUTHOR

Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Arthur Axel "fREW" Schmidt.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.