| Query 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 about the query: | The query does not take into account different field sizes. |
| Query type: | Sofware measure (Numeric values (software measures) about the database) |
| Query license: | MIT License |
| Data source: | INFORMATION_SCHEMA only |
| SQL query: | Click on query to copy it
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, ',<br>' ORDER BY data_type) AS data_types FROM types; |
| Collection name | Collection description |
|---|---|
| Find problems about base tables | A 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 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 . |
| Find quick numeric overview of the database | Queries that return numeric values showing mostly the number of different types of database objects in the database |
| Category name | Category description |
|---|---|
| Data types | Queries of this category provide information about the data types and their usage. |