Catalog Pg Attrdef – ProtonBase 文档

`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 pg_attrdef Columns

Column Type Description

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

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.