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52.6. `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.

Table 52.6. pg_attrdef Columns

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.

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https://www.postgresql.org/docs/18/catalog-pg-attrdef.html

52.6. pg_attrdef

52.6. `pg_attrdef`