diff options
| -rw-r--r-- | Bugzilla/DB/Schema/Mysql.pm | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/Bugzilla/DB/Schema/Mysql.pm b/Bugzilla/DB/Schema/Mysql.pm index 627716970..49e6add1a 100644 --- a/Bugzilla/DB/Schema/Mysql.pm +++ b/Bugzilla/DB/Schema/Mysql.pm @@ -178,13 +178,33 @@ sub get_alter_column_ddl { delete $new_def_copy{PRIMARYKEY}; } - my $new_ddl = $self->get_type_ddl(\%new_def_copy); my @statements; push(@statements, "UPDATE $table SET $column = $set_nulls_to WHERE $column IS NULL") if defined $set_nulls_to; - push(@statements, "ALTER TABLE $table CHANGE COLUMN + + # Calling SET DEFAULT or DROP DEFAULT is *way* faster than calling + # CHANGE COLUMN, so just do that if we're just changing the default. + my %old_defaultless = %$old_def; + my %new_defaultless = %$new_def; + delete $old_defaultless{DEFAULT}; + delete $new_defaultless{DEFAULT}; + if ($self->columns_equal(\%new_defaultless, \%old_defaultless)) { + if (defined $old_def->{DEFAULT} and !defined $new_def->{DEFAULT}) { + push(@statements, + "ALTER TABLE $table ALTER COLUMN $column DROP DEFAULT"); + } + else { + push(@statements, "ALTER TABLE $table ALTER COLUMN $column + SET DEFAULT " . $new_def->{DEFAULT}); + } + } + else { + my $new_ddl = $self->get_type_ddl(\%new_def_copy); + push(@statements, "ALTER TABLE $table CHANGE COLUMN $column $column $new_ddl"); + } + if ($old_def->{PRIMARYKEY} && !$new_def->{PRIMARYKEY}) { # Dropping a PRIMARY KEY needs an explicit DROP PRIMARY KEY push(@statements, "ALTER TABLE $table DROP PRIMARY KEY"); |