Goal 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.)
License MIT (opens in new tab)
Data Source INFORMATION_SCHEMA only
SQL Query
SELECT domain_schema, domain_name, Count(*) AS number_of_usages, string_agg(table_schema || '.' || table_name || '.' || column_name, ';<br>' 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:

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 .

NameDescription
Find problems by overviewQueries 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:

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.

NameDescription
Comfortability of database evolutionQueries of this category provide information about the means that influence database evolution.
DomainsQueries of this category provide information about reusable specifications of column properties.