+
+ public static function schemaDef()
+ {
+ return array(
+ 'description' => 'To avoid checking database structure all the time, we store a checksum of the expected schema info for each table here. If it has not changed since the last time we checked the table, we can leave it as is.',
+ 'fields' => array(
+ 'table_name' => array('type' => 'varchar', 'length' => '64', 'not null' => true, 'description' => 'Table name'),
+ 'checksum' => array('type' => 'varchar', 'length' => '64', 'not null' => true, 'description' => 'Checksum of schema array; a mismatch indicates we should check the table more thoroughly.'),
+ 'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
+ ),
+ 'primary key' => array('table_name'),
+ );
+ }