Goal Find the number of different data types that are used to define base table columns as well as list all the different types. Data type constrains values in a column. Thus, in case there is a small number of used types, it raises a question as to whether the types have been optimally selected.
Notes The query does not take into account different field sizes.
Type Sofware measure (Numeric values (software measures) about the database)
License MIT License
Data Source INFORMATION_SCHEMA only
SQL Query
WITH types AS (SELECT DISTINCT CASE WHEN data_type='USER-DEFINED' THEN udt_name || '(' || data_type || ')' ELSE data_type END AS data_type
FROM INFORMATION_SCHEMA.columns INNER JOIN INFORMATION_SCHEMA.tables USING (table_schema, table_name)
WHERE table_type='BASE TABLE'
AND table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL))
SELECT Count(data_type) AS number_of_different_data_types, string_agg(data_type, ',
' ORDER BY data_type) AS data_types FROM types;
Collections

This query belongs to the following collections:

NameDescription
Find problems about base tablesA selection of queries that return information about the data types, field sizes, default values as well as general structure of base tables. Contains all the types of queries - problem detection, software measure, and general overview
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 .
Find quick numeric overview of the databaseQueries that return numeric values showing mostly the number of different types of database objects in the database
Categories

This query is classified under the following categories:

NameDescription
Data typesQueries of this category provide information about the data types and their usage.