| 881 |
Composite foreign keys with a mix of mandatory and optional columns |
Find composite foreign keys with a mix of mandatory and optional columns. In case of a composite foreign keys all the columns should either optional or mandatory in order to avoid problems with NULLs. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 882 |
Composite foreign keys with an incorrect order of columns (ver 1) |
Find composite foreign keys where the order of columns does not correspond to the order of columns in the referenced candidate key. Find composite foreign keys in case of which the foreign key and candidate key consist of columns with the same name but the order of columns in the keys is different. For instance, the query returns information about a foreign key (personal_code, country_code) that refers to the candidate key (country_code, personal_code). In SQL keys are ordered sets of columns. Thus, in case of composite foreign key declarations one has to pay attention that the order of columns in the FOREIGN KEY clause matches the order of columns in the REFERENCES clause. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 883 |
Composite foreign keys with an incorrect order of columns (ver 2) |
Find composite foreign keys where the order of columns does not correspond to the order of columns in the referenced candidate key. Find composite foreign keys in case of which the foreign key and candidate key are not the same in terms of data types of the columns. For instance, the query returns information about a foreign key that columns have the types (SMALLINT, INTEGER) that refers to the candidate key that columns have the types (INTEGER, SMALLINT). In SQL keys are ordered sets of columns. Thus, in case of composite foreign key declarations one has to pay attention that the order of columns in the FOREIGN KEY clause matches the order of columns in the REFERENCES clause. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 884 |
Constraints that are not redefined in a subtable |
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) |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 885 |
Constraints that are redefined in a subtable. |
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. |
General |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 886 |
Constraint-supporting UNIQUE indexes with the same leading column |
Find indexes that support a uniqueness constraint and have the same leading column. |
General |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 887 |
Constraints with the same name within the same schema and constraint type |
Find names of foreign key constraints that are used within the same schema more than once. Find names of check constraints that are used within the same schema more than once. Find names of constraint triggers that are used within the same schema more than once. Different things should have different names. But here different constraints have the same name. Also make sure that this is not a sign of duplication. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 888 |
Cycle in a hierarchy |
There should not be cycles in hierarchies meaning that the parent must always be specified. In this case a parent must reference to a child or to itself, otherwise it cannot be registered. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 889 |
Database can be accessed through PUBLIC privileges |
Find as to whether the database access by users (applications) can take place thanks to PUBLIC privileges, i.e., find as to whether PUBLIC (all current and future users) has CONNECT privilege in the database. PUBLIC gets the privilege by default. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 890 |
Data type mismatch in check constraints |
This query identifies single-column CHECK constraints where the validation logic utilizes operators or functions that are incompatible with the column's native data type. It detects cases where the database must perform implicit casting to evaluate the expression (e.g., performing arithmetic on a TEXT column or string manipulation on a DATE column). Relying on implicit coercion in constraints involves unnecessary computational overhead and frequently indicates a fundamental error in data modeling or constraint formulation. |
Problem detection |
system catalog base tables only |
2025-12-05 19:23 |
MIT License |
View |
| 891 |
Deferrable constraints |
Find all deferrable constraints. |
General |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 892 |
Deferrable foreign key constraint with a RESTRICT compensating action |
Find deferrable foreign key constraint with ON UPDATE RESTRICT or ON DELETE RESTRICT compensating action. Referential actions are carried out before, and are not part of, the checking of a referential constraint. Deferring a referential constraint defers the checking of the of the constraint (a ) but does not defer the referential actions of the referential constraint. In PostgreSQL the essential difference between NO ACTION and RESTRICT is that NO ACTION allows the check to be deferred until later in the transaction, whereas RESTRICT does not. Thus RESTRICT could result with the failure of data modification where in case of NO ACTION the modification would succeed. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 893 |
Definition of a non-minimal superkey instead of a candidate key (based on key constraints) |
Find primary key, unique constraints, and exclude constraints wiht only operator = (i.e., sets of columns) that are proper subsets of other primary key, unique, and exclude constraints of the same table. Candidate key is a minimal superkey, meaning that it is not possible to remove columns from the candidate key without losing its uniqueness property. One should define primary key's and unique constraints based on candidate keys, i.e., the keys should not have redundancy in terms of columns. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 894 |
Definition of a non-minimal superkey instead of a candidate key (based on unique indexes) |
Find pairs of non-partial unique indexes where the columns of a index are a proper subset of the columns of another index. Include indexes that support a constraint (primary key, unique, exclude), i.e., these indexes have been automatically created due to the constraint declaration. Exclude the pairs where both participants have been created to support a constraint. Candidate key is a minimal superkey, meaning that it is not possible to remove columns from the candidate key without losing its uniqueness property. One should define keys based on candidate keys, i.e., the keys should not have redundancy in terms of columns. Defining a unique index essentially means defining a key in the table but it is done at the lower level of abstraction. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 895 |
Depth of referential tree of a schema |
Depth of referential tree of a database schema is the longest referential path between the tables in this schema (Piattini et al., 2001). In other words, it is the biggest value among the DRT(T) values of all the tables of the schema. |
Sofware measure |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 896 |
Depth of relational tree of a table |
Depth of relational tree of a table T (DRT(T)) is defined by Piattini et al. (2001) as "the longest referential path between tables, from the table T to any other table in the schema". The result may help to classify the data. If the depth is 0, then probably the table contains classifers. Tables with the largest depth probably contain some extra information about main entities. |
Sofware measure |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 897 |
Derived table names have prefix or suffix |
Find the names of views and materialized views that have prefix or suffix. Follow the same naming style as in case of base tables (derived tables are also tables). Thus, if base tables do not have prefixes or suffixes, then derived tables shouldn't have these as well. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 898 |
Different foreign key column names in case of referencing the same candidate key |
Find the cases when the names of columns in different foreign keys that reference to the same candidate key are different. If different names reflect different roles, then it is legitimate. However, there could also be accidental differences that makes it more difficult to use the database. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 899 |
Different prefixes of a candidate key column and a referencing foreign key column |
The naming must be consistent. Find foreign key constraints where the candidate key column and foreign key column names have different prefixes. Thus, for instance, one cannot use USING syntax for joining the tables. |
Problem detection |
system catalog base tables only |
2025-11-07 10:11 |
MIT License |
View |
| 900 |
Different suffixes of a candidate key column and a referencing foreign key column |
This query identifies naming inconsistencies in foreign key relationships by comparing the suffixes of foreign key columns against their referenced candidate key columns. It flags pairs where the suffixes diverge (e.g., referencing user_id via a column named user_code or user_ref). Such discrepancies prevent the use of the simplified ANSI SQL USING syntax for joins, forcing the use of explicit ON clauses. The goal is to enforce a standardized suffix convention (typically _id) across the schema to improve maintainability and query readability. |
Problem detection |
system catalog base tables only |
2025-12-14 11:43 |
MIT License |
View |