| Query goal: | Find derived tables (views and materialized views) that contain more than one DISTINCT invocation. Make sure that the query is correctly written, including that it does not have unwanted formation of a Cartesian product. |
| Notes about the query: | In the returned subquery of view/materialized view the query replaces each newline character with the line break (br) tag for the better readability in case the query result is displayed in a web browser. |
| Query type: | General (Overview of some aspect of the database.) |
| Query license: | MIT License |
| Data source: | INFORMATION_SCHEMA+system catalog |
| SQL query: | Click on query to copy it
SELECT table_schema, table_name, type, regexp_replace(view_definition,'[\r\n]','<br>','g') AS view_definition FROM (SELECT views.table_schema, views.table_name, 'VIEW' AS type, views.view_definition FROM information_schema.views WHERE 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) UNION SELECT schemaname, matviewname, 'MATERIALIZED VIEW' AS type, regexp_replace(definition,'[\r\n]','<br>','g') AS definition FROM pg_catalog.pg_matviews) AS foo WHERE view_definition ~*'[[:space:]]distinct[[:space:]].+[[:space:]]distinct[[:space:]]' ORDER BY table_schema, table_name; |
| Collection name | Collection 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 . |
| Category name | Category description |
|---|---|
| Derived tables | Queries of this category provide information about the derived tables (views, materialized views), which are used to implement virtual data layer. |