When exactly is GrowDB fired?

[MCMartin]

Is GrowDB fired after the file have been grown or before?

[johnsmirnios · Accepted solution]

Essentially, it is after the file has grown. For dbspaces, the OS has grown the file before the event is signalled; however, the server usually initializes the new pages asynchronously afterwards. If the database goes down dirty while the async initialization is taking place, the newly allocated space is not considered to be part of the dbspace (ie, the database will only retain the new space if the async initialization completes).