52.6. pg_attrdef

pg_attrdef

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

Column Type Description
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 or generation expression, in `nodeToString()` representation. Use `pg_get_expr(adbin, adrelid)` to convert it to an SQL expression.

Column Type

Description

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 or generation expression, in nodeToString() representation. Use pg_get_expr(adbin, adrelid) to convert it to an SQL expression.

: pg_attrdef Columns