statistics_info support

diff --git a/Changes b/Changes
index c36f3a1..08d4aa7 100644 (file)
--- a/Changes
+++ b/Changes
@@ -1,5 +1,8 @@
 Revision history for Perl extension DBIx::Class::Schema::Loader
 
+        - Added support for DBI's new standard "statistics_info"
+          method to gather unique key info (only supported by
+          DBD::Pg trunk + DBI >= 1.52 so far)
         - columns_info_for imported from DBIx::Class
         - relationships are now on by default, use skip_relationships
           to disable them

diff --git a/lib/DBIx/Class/Schema/Loader/DBI.pm b/lib/DBIx/Class/Schema/Loader/DBI.pm
index 5383a03..f21489a 100644 (file)
--- a/lib/DBIx/Class/Schema/Loader/DBI.pm
+++ b/lib/DBIx/Class/Schema/Loader/DBI.pm
@@ -114,7 +114,7 @@ sub _table_columns {
 
 # Returns arrayref of pk col names
 sub _table_pk_info { 
-    my ( $self, $table ) = @_;
+    my ($self, $table) = @_;
 
     my $dbh = $self->schema->storage->dbh;
 
@@ -124,10 +124,40 @@ sub _table_pk_info {
     return \@primary;
 }
 
-# Override this for uniq info
+# Override this for vendor-specific uniq info
 sub _table_uniq_info {
-    warn "No UNIQUE constraint information can be gathered for this vendor";
-    return [];
+    my ($self, $table) = @_;
+
+    my $dbh = $self->schema->storage->dbh;
+    if(!$dbh->can('statistics_info')) {
+        warn "No UNIQUE constraint information can be gathered for this vendor";
+        return [];
+    }
+
+    my %indices;
+    my $sth = $dbh->statistics_info(undef, $self->db_schema, $table, 1, 1);
+    while(my $row = $sth->fetchrow_hashref) {
+        # skip table-level stats, conditional indexes, and any index missing
+        #  critical fields
+        next if $row->{TYPE} eq 'table'
+            || defined $row->{FILTER_CONDITION}
+            || !$row->{INDEX_NAME}
+            || !defined $row->{ORDINAL_POSITION}
+            || !$row->{COLUMN_NAME};
+
+        $indices{$row->{INDEX_NAME}}->{$row->{ORDINAL_POSITION}} = $row->{COLUMN_NAME};
+    }
+
+    my @retval;
+    foreach my $index_name (keys %indices) {
+        my $index = $indices{$index_name};
+        push(@retval, [ $index_name => [
+            map { $index->{$_} }
+                sort keys %$index
+        ]]);
+    }
+
+    return \@retval;
 }
 
 # Find relationships

diff --git a/lib/DBIx/Class/Schema/Loader/DBI/Pg.pm b/lib/DBIx/Class/Schema/Loader/DBI/Pg.pm
index 5f4ae7c..e599b32 100644 (file)
--- a/lib/DBIx/Class/Schema/Loader/DBI/Pg.pm
+++ b/lib/DBIx/Class/Schema/Loader/DBI/Pg.pm
@@ -38,6 +38,11 @@ sub _setup {
 sub _table_uniq_info {
     my ($self, $table) = @_;
 
+    # Use the default support if available
+    return $self->next::method($table)
+        if $DBI::VERSION >= 1.52
+            && $DBD::Pg::VERSION >= 1.50;
+
     my @uniqs;
     my $dbh = $self->schema->storage->dbh;