// Split the key into schema and table for querying.
list($schema,$table_name)=explode('.',$key);
$table_information=(object)array(
'blob_fields'=>array(),
'sequences'=>array(),
);
// Don't use {} around information_schema.columns table.
$result=$this->connection->query("SELECT column_name, data_type, column_default FROM information_schema.columns WHERE table_schema = :schema AND table_name = :table AND (data_type = 'bytea' OR (numeric_precision IS NOT NULL AND column_default LIKE :default))",array(
':schema'=>$schema,
':table'=>$table_name,
':default'=>'%nextval%',
// The bytea columns and sequences for a table can be found in
// pg_attribute, which is significantly faster than querying the
// information_schema. The data type of a field can be found by lookup
// of the attribute ID, and the default value must be extracted from the
// node tree for the attribute definition instead of the historical
// human-readable column, adsrc.
$sql=<<<'EOD'
SELECT pg_attribute.attname AS column_name, format_type(pg_attribute.atttypid, pg_attribute.atttypmod) AS data_type, pg_get_expr(pg_attrdef.adbin, pg_attribute.attrelid) AS column_default
FROM pg_attribute
LEFT JOIN pg_attrdef ON pg_attrdef.adrelid = pg_attribute.attrelid AND pg_attrdef.adnum = pg_attribute.attnum
WHERE pg_attribute.attnum > 0
AND NOT pg_attribute.attisdropped
AND pg_attribute.attrelid = :key::regclass
AND (format_type(pg_attribute.atttypid, pg_attribute.atttypmod) = 'bytea'
