On Tue, Nov 19, 2024 at 11:45 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Pavel Stehule <pavel.stehule@gmail.com> writes: > út 19. 11. 2024 v 18:51 odesílatel Michel Pelletier < > pelletier.michel@gmail.com> napsal: >> A couple years ago I tried to compress what I learned about expanded >> objects into a dummy extension that just provides the necessary >> boilerplate. It wasn't great but a start: >> https://github.com/michelp/pgexpanded >> Pavel Stehule indicated this might be a good example to put into contrib:
> another position can be src/test/modules - I think so your example is > "similar" to plsample
Yeah. I think we've largely adopted the position that contrib should contain installable modules that do something potentially useful to end-users. A pure skeleton wouldn't be that, but if it's fleshed out enough to be test code for some core features then src/test/modules could be a reasonable home.
I've circled back on this task to do some work improving the skeleton code, but going back through our thread I landed on this point Tom made about usefulness vs pure skeleton and my natural desire is to make a simple expanded object that is also useful, so I brainstormed a bit and decided to try something relatively simple but also (IMO) quite useful, an expanded datum that wraps sqlite's serialize/derserialize API:
As crazy as this sounds there are some good use cases here, very easy to stuff relational data into a completely isolated box without having to worry about things like very granular RLS policies or other issues of traditional postgres multi-tenancy. Being wire compatible with sqlite-wasm also means databases can be slurped right from postgres into a browser and synced with no need to transform data back and forth. Large chunks of complex structured relational data can be wiped out with a simple row deletion, and since sqlite can't escape from its box and has no scripting ability, it makes a nice secure sandbox that even if users could corrupt it, it would have minimal impact on Postgres.
It's only a bit more complicated than the pgexpanded skeleton and the expanded datum bits are is their own separate C file so they can be studied in isolation. Based on the above comments, this seems something more appropriate for contrib than test/modules, although I can see there may be some understandable pushback about something so weird that also has an external library dependency.
Any thoughts? I want to nail down the core functionality before I go back and clean up either case based on Tom review comments on the skeleton module (most of which still apply since I used the skeleton to make it!)
