[Tarantool-patches] [PATCH 3/4] box: provide a user friendly frontend for accessing session settings

[Vladislav Shpilevoy]

On 16/03/2020 17:08, Nikita Pettik wrote:
> On 17 Feb 15:12, Chris Sosnin wrote:
>> - space_object:update() is hard to use for configuring session settings,
>> so we provide box.session.setting table, which can be used in a much more
>> native way.
>>
>> - Prior to this patch sql settings were not accessible before box.cfg()
>> call, even though these flags can be set right after session creation.
>>
>> Part of #4711
>> ---
> 
> tarantool> box.session.settings.sql_vdbe_debug
> ---
> - false
> ...
> 
> tarantool> box.session.settings.sql_vdbe_debug = true
> ---
> ...
> 
> tarantool> box.session.settings.sql_vdbe_debug
> ---
> - true
> ...

Yeah, we can ban this. To avoid confusion.

> 
> tarantool> box.execute("select 1")
> ---
> - metadata:
>   - name: '1'
>     type: integer
>   rows:
>   - [1]
> ...
> 
> Looks inconsistent. Can we use instead of :set() method simple
> table value assignment? Otherwise accessing row table values

Assignment would require not to store settings in box.session.settings,
to be able to redefine __newindex metamethod. If we don't store them, we
kill autocompletion, which was asked explicitly by somebody.

But I am on your side here - I don't think autocompletion worth this
complication. Who wants to look at existing settings can just print
box.sessions.settings table.

> should be disallowed. Same concerns :get() method. Why ever
> anyone should bother with :get() when one can access table value
> via simple indexing?

Hm. But there is no :get() method. We didn't implement getting, because
no one asked for this. And indeed, usually you just set settings, without
checking if set really worked. I was thinking we could introduce get if
someone asks for that. But up to you. Can be added now as well.