PostgreSQL Query Catalog

Find all the base tables that serve as supertables in the inheritance hierarchies

Find primary key, unique, foreign key, and exclude constraints that have been defined in tables that participate in an inheritance hierarchy. Do not forget to redefine the constraints that are defined on supertables also on their subtables.

Find columns that have been added to a subtable, i.e., these were not defined in its immediate supertable.

Find primary key, unique, foreign key, and exclude constraints that have been defined in a supertable (parent table) but not in its subtable. Unfortunately, PostgreSQL table inheritance is implemented in a manner that some constraints (CHECK, NOT NULL) are inherited from the supertable but others are not. "All check constraints and not-null constraints on a parent table are automatically inherited by its children, unless explicitly specified otherwise with NO INHERIT clauses. Other types of constraints (unique, primary key, and foreign key constraints) are not inherited." (PostgreSQL documentation)

Find primary key, unique, foreign key, and exclude constraints that have been defined in a supertable (parent table) but not in its subtable. Additional condition is that in case of the subtable there is no CHECK that permits only one specific value in the constraint column. The presence of such check would make the design acceptable. Unfortunately, PostgreSQL table inheritance is implemented in a manner that some constraints (CHECK, NOT NULL) are inherited from the supertable but others are not. "All check constraints and not-null constraints on a parent table are automatically inherited by its children, unless explicitly specified otherwise with NO INHERIT clauses. Other types of constraints (unique, primary key, and foreign key constraints) are not inherited." (PostgreSQL documentation)

Find primary key, unique, foreign key, and exclude constraints that have been defined in a supertable (parent table) but not in its subtable. Exclude constraints where in case of the subtable there is a CHECK that permits only one specific value in the constraint column. The presence of such check would make the design acceptable. Unfortunately, PostgreSQL table inheritance is implemented in a manner that some constraints (CHECK, NOT NULL) are inherited from the supertable but others are not. "All check constraints and not-null constraints on a parent table are automatically inherited by its children, unless explicitly specified otherwise with NO INHERIT clauses. Other types of constraints (unique, primary key, and foreign key constraints) are not inherited." (PostgreSQL documentation)

Find primary key, unique, foreign key, and exclude constraints that have been defined in a supertable (parent table) and have been redefined in its subtable.

Find foreign key constraints that refer to a base table that has at least one subtable in the inheritance hierarchy. Rows of the subtable do not belong to the supertable in terms of checking the referential integrity. Let us assume that there is a table T with a subtable Tsub. Let us also assume that table B has a foreign key that refers to the table T. If a row is inserted into Tsub, then this row cannot be referenced from B.

Find instances of multiple inheriance of base tables. Make sure that multiple inheritance is indeed needed.

Find CHECK constraints that have been defined in a supertable (parent table) but not in its subtables. An entity that belongs to a subtype should also belong to its supertype. If a subtype entity satisfies some constraint, then logically it must also satisfy the constraints of the supertype as well. If CHECK constraints are not inherited, then this is not guaranteed. If you implement subtyping not merely reuse implementation in the subtables, then the subtables must have at least the same CHECK constraints as the supertable. CHECK(false) on a supertable is an appropriate CHECK constraint if one wants to prevent registering data directly to the supertable, i.e., data can only be added to the subtables.

Find base table CHECK constraints that have been defined as NOT INHERITED but the constraint with the same Boolean expression has been defined in the immediate subtable of the table.

Find CHECK constraints that cover at least one column and that have been defined in a supertable (parent table) but not in its subtables. An entity that belongs to a subtype should also belong to its supertype. If a subtype entity satisfies some constraint, then logically it must also satisfy the constraints of the supertype as well. If CHECK constraints are not inherited, then this is not guaranteed. If you implement subtyping not merely reuse implementation in the subtables, then the subtables must have at least the same CHECK constraints as the supertable.

Find columns of base tables or foreign tables in case of which a check constraint on the column permits only one value in the column. Exclude columns that are inherited from a supertable because the constraint may be correct if it is applied to a column of a subtable that is inherited from the supertable.

Find inheritance between base tables. Use table inheritance carefully because, for instance, certain constraints are not inherited and must be redefined on child tables.

Find in case of each base table that participates in a table inheritance hierarchy the path to the table from the top-level table. Use table inheritance carefully because, for instance, certain constraints are not inherited and must be redefined on child tables. Also make sure that the identifier of each child table in an inheritance hierarchy is a hyponym of the identifier of its parent table.

Find the number of direct and all (direct+indirect) child tables of a base table based on the table inheritance.