First time?

• Wanna move column in a table 'cause it hurts your inner perfectionist?
• You new CTO/DBA decided that your current table layout must be optimized by 4 bytes per row or business will fail?
• Your code standards changed and all inner joins must be rewritten with where again?
• Uhm, why not to add some other columns for our primary table?
• Simple grep in your migration directory for view definition give you 20 results?
• You look at your migration and see copy-pasted 1000 sloc of other migrations. And the same for rollback?!

What is this

Complex enhancement/refactoring of https://gist.github.com/mateuszwenus/11187288
See related topics https://wiki.postgresql.org/wiki/Todo#Views_and_Rules

Recursively backup all dependent views, then modify base tables, then recreate all backuped views

Supported features

Feature	View	Materialized View	Comment
Create view	Yes	Yes	With reloptions, tablespace, (no) data
Create index	N/A	Yes
Alter owner to	Yes	Yes
Create rule	Yes	Yes
Comment on view	Yes	Yes
Comment on view column	Yes	Yes
Grant privilege on view	Yes	Yes	With grant options
Grant privilege on view column	Yes	Yes	With grant options
Create policy	N/A	N/A

Usage

select public.deps_save_and_drop_dependencies(
  'public',
  'my_table',
  '{
    "dry_run": true,
    "verbose": false,
    "populate_materialized_view": false
  }'
);

-- alter my_table...

select public.deps_restore_dependencies(
  'public',
  'my_table',
  '{
    "dry_run": true,
    "verbose": false
  }'
);

Options

• deps_save_and_drop_dependencies

  • dry_run Run without actually dropping dependencies
  • verbose Show debug log
  • populate_materialized_view Enable or disable materialized view refresh-on-create via WITH [NO] DATA flag

• deps_restore_dependencies

  • dry_run Run without actually executing ddl statements
  • verbose Show debug log