This query identifies identity columns defined with the GENERATED BY DEFAULT clause. Unlike GENERATED ALWAYS, this configuration permits manual insertion of values into the identity column without explicit overrides. This flexibility creates a significant risk of sequence desynchronization: if a user manually inserts a key value that exceeds the current sequence state, the sequence will eventually generate a colliding value. This results in runtime unique constraint violations (primary key conflicts) that are difficult to predict and resolve. The preferred pattern for surrogate keys is typically GENERATED ALWAYS to enforce system-controlled uniqueness.
Type
Problem detection (Each row in the result could represent a flaw in the design)
SELECT c.table_schema, c.table_name , c.column_name
FROM information_schema.columns c
INNER JOIN information_schema.schemata s
ON c.table_schema=s.schema_name
WHERE c.is_identity='YES'
AND identity_generation='BY DEFAULT'
AND (c.table_schema = 'public'
OR s.schema_owner<>'postgres')
ORDER BY c.table_schema, c.table_name , c.column_name;
Collections
This query belongs to the following collections:
Name
Description
Find problems automatically
Queries, that results point to problems in the database. Each query in the collection produces an initial assessment. However, a human reviewer has the final say as to whether there is a problem or not .
Categories
This query is classified under the following categories:
Name
Description
Comfortability of data management
Queries of this category provide information about the means that have been used to make the use or management of database more comfortable and thus, more efficient.
Sequence generators
Queries of this category provide information about sequence generators and their usage.
Uniqueness
Queries of this category provide information about uniqueness constraints (PRIMARY KEY, UNIQUE, EXCLUDE) as well as unique indexes.