perfomance degradation for large view definitions

There seems to be something going wrong with the structure view for views with large/complex queries.

Viewing the structure of `information_schema.routines` vs `information_schema.sequences` i a good example. `routines` is noticeably slow compared to `sequences` on my machine (2016 15'' MacBook Pro).

No file, test, or entry point is named. First reproduce the structure view for information_schema.routines and information_schema.sequences, then trace the code used to load and display large or complex view definitions. Done means identifying and fixing the cause of the noticeable performance difference and verifying both examples again.

Written by the indexing model from the issue text.