Merge lp:~jonathan-cua/percona-toolkit/percona-toolkit into lp:percona-toolkit/2.2

[Jonathan Cua]

This adds an option to use "CREATE TABLE LIKE" construct to preserve the index. One use case of this is this scenario: slave database has more index than the master. With this option, it will allow the slave to retain its old indexes. There is danger to this in that if the slave already has the index, and this option was used, then it will break replication.

Unmerged revisions

582. By Jonathan Cua on 2013-06-06

Add create-table-like option

=== modified file 'bin/pt-online-schema-change'
--- bin/pt-online-schema-change	2013-04-19 23:26:48 +0000
+++ bin/pt-online-schema-change	2013-06-07 00:30:38 +0000
@@ -7750,6 +7750,10 @@
       $tbl = $dsn->{t};  
    }
 
+   if ( $o->get('create-table-like') ) {
+      $o->set('alter-foreign-keys-method', 'none')
+   }
+
    my $alter_fk_method = $o->get('alter-foreign-keys-method') || '';
    if ( $alter_fk_method eq 'drop_swap' ) {
       $o->set('swap-tables',    0);
@@ -9488,7 +9492,14 @@
       # or another table, we can still have a collision. But if there are
       # multiple FKs on this table, it's hard to know which one is causing the
       # trouble. Should we generate random/UUID FK names or something instead?
-      my $sql    = $ddl;
+      my $sql;
+      if ( $o->get('create-table-like') ) {
+         $sql = "CREATE TABLE $table_name LIKE " . $orig_tbl->{tbl} . "\n";
+      }
+      else {
+         $sql = $ddl;
+      }
+
       $sql       =~ s/\ACREATE TABLE .*?\($/CREATE TABLE $quoted (/m;
       $sql       =~ s/^  CONSTRAINT `/  CONSTRAINT `_/gm;
       if ( $o->get('default-engine') ) {
@@ -10554,6 +10565,13 @@
 
 =over
 
+=item --create-table-like
+
+Use the create table like construct to preserve the index of the original table.
+This will skip anything related to foreign keys.
+
+=over
+
 =item auto
 
 Automatically determine which method is best.  The tool uses