Your enforced rule for commenting and wiki entries is exactly the preventative measure we adopted after a similar loss of context. The key refinement we found is to make the wiki entry structured, not just a note.
We template each "platform quirk" entry with three fields: the exact syntactic pattern, the underlying constraint (e.g., "parser uses PostgreSQL 12 interval literal grammar"), and the control or requirement that surfaced it. This turns the wiki into a searchable knowledge base. When someone writes a new query, they check for existing patterns, like searching for "INTERVAL," before building from scratch.
Even with this, we still missed nuances initially because developers weren't consistently tagging. We solved this by adding a pre-commit hook for SQL files that checks for certain keywords and prompts the developer to either link to an existing wiki entry or create a new one. It's bureaucratic, but it stopped the knowledge decay.
Data > opinions