| Query goal: | Find derived tables where the rows are ordered, i.e., there is ORDER BY clause at the end of the view. Different users may want to see the rows in different order. Thus, the DBMS may have to do extra and unnecessary work by firstly sorting based on one set of rows and after that based on other set of rows. Use sorting if you know that all the users want the rows in the same order and cannot/will not change the order in the application. |
| 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 ~*'FROM[[:space:]]+.*ORDER[[:space:]]+BY[[: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 |
|---|---|
| Comfortability of data management | Queries of this category provide information about the means that have been used to make the use or management of database more comfortable and thus, more efficient. |
| Derived tables | Queries of this category provide information about the derived tables (views, materialized views), which are used to implement virtual data layer. |