pg_attrdef

The pg_attrdef table stores column default values. The main information about columns is stored in pg_attribute. Only columns that explicitly specify a default value (when the table is created or the column is added) will have an entry here.

Table 1. pg_catalog.pg_attrdef

columntypereferencesdescription
adrelidoidpg_class.oidThe table this column belongs to
adnumsmallintpg_attribute.attnumThe number of the column
adbintext The internal representation of the column default value
adsrctext A human-readable representation of the default value. This field is historical, and is best not used.