52.6. pg_attrdef

The catalog pg_attrdef stores column default values. The main information about columns is stored in pg_attribute . Only columns for which a default value has been explicitly set will have an entry here.

Table 52.6. pg_attrdef Columns

Column Type


oid oid

Row identifier

adrelid oid (references pg_class . oid )

The table this column belongs to

adnum int2 (references pg_attribute . attnum )

The number of the column

adbin pg_node_tree

The column default value, in nodeToString() representation. Use pg_get_expr(adbin, adrelid) to convert it to an SQL expression.