Incomplete PRAGMA support

[rickhull]

I have noticed some inconsistencies in the handling for SQLite pragmas.

1. There is a setter for busy_timeout= but no getter. Likewise for ignore_check_constraints=.
2. No accessors for analysis_limit hard_heap_limit trusted_schema
3. No method for optimize
4. No methods for function_list module_list pragma_list
5. No methods for table_list table_xinfo

For the last, SQLite supports 3 pragmas for index and table:

• thing_list
• thing_info
• thing_xinfo

The gem I have installed, version 2.0.4, has methods for all three index pragmas but only the table_info method.

Some of these may not make sense to support, but these are my findings. Separately, I have some ideas about how to reorganize lib/sqlite3/pragmas.rb.

[flavorjones]

@rickhull Thank you for pointing this out!

If you'd like to get some easy PRs in, I'd be very grateful for your help with these! If not, I'll leave this open as a note for other contributors.

[rickhull]

I might take a stab. Here's what I'm doing in the meantime: https://gist.github.com/rickhull/464c6fdf5fdea217894f67618b4a2b0c

[rickhull]

Please take a look at the Nostrb::SQLite::Pragma class: https://github.com/rickhull/nostrb/blob/master/lib/nostrb/sqlite.rb#L6

I want to basically import this wholesale, or something like it, as our pragma backend. We can then patch or rewrite the current API using this backend. I think it will be relatively easy to delete nearly of the current pragma impl with this more programmatic approach.

Even if not, I may still look at extending the current approach.