Find for each domain the number of usages in base tables. The less you have managed to reuse domains in case of different columns, the more you have wasted your time by creating the domains.
Notes
In case of the string_agg function, the line break (br) tag is used as a part of the separator for the better readability in case the query result is displayed in a web browser.
Type
General (Overview of some aspect of the database.)
SELECT domain_schema, domain_name, Count(*) AS number_of_usages, string_agg(table_schema || '.' || table_name || '.' || column_name, '; ' ORDER BY table_schema, table_name, column_name) AS columns
FROM Information_schema.column_domain_usage
WHERE domain_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
AND (table_schema, table_name) IN (SELECT table_schema, table_name
FROM INFORMATION_SCHEMA.tables WHERE table_type='BASE TABLE')
GROUP BY domain_schema, domain_name
ORDER BY count(*) DESC, domain_schema, domain_name;
Collections
This query belongs to the following collections:
Name
Description
Find problems by overview
Queries that results point to different aspects of database that might have problems. A human reviewer has to decide based on the results as to whether there are problems or not .
Categories
This query is classified under the following categories:
Name
Description
Comfortability of database evolution
Queries of this category provide information about the means that influence database evolution.
Domains
Queries of this category provide information about reusable specifications of column properties.