Getting the views dependency tree

When refactoring a certain view, such as adding a new column or changing the column type, one needs to refactor all the views that depend on this particular view. Unfortunately, PostgreSQL does not provide the means to create a logical dump of dependent object.

Getting ready

PostgreSQL provides pg_dump to dump a certain database or a specific set of objects in a database. Also, in development, it is recommended to keep the code in a GIT repository.

Unfortunately, often the SQL code for legacy applications is not maintained in the version control system. In this case, if there is requirement to change a certain view definition or even a column type, it is necessary to identify the affected views, dump them, and then restore them.

How to do it…

The first step is to identify the views to be dropped and restored. Depending on the task, one can write different scripts; a common pattern is to drop the views depending on a certain view, table, or table column. The base...