Re: Allow table AMs to define their own reloptions

On Sun, Mar 02, 2025 at 09:56:41AM +0100, Julien Tachoires wrote:
> With the help of the new TAM routine 'relation_options', table access
> methods can with this patch define their own reloptions
> parser/validator.
>
> These reloptions can be set via the following commands:
> 1. CREATE TABLE ... USING table_am
> WITH (option1='value1', option2='value2');
> 2. ALTER TABLE ...
> SET (option1 'value1', option2 'value2');
> 3. ALTER TABLE ... SET ACCESS METHOD table_am
> OPTIONS (option1 'value1', option2 'value2');
>
> When changing table's access method, the settings inherited from the
> former TAM can be dropped (if not supported by the new TAM) via: DROP
> option, or, updated via: SET option 'value'.
>
> Currently, tables using different TAMs than heap are able to use heap's
> reloptions (fillfactor, toast_tuple_target, etc...). With this patch
> applied, this is not the case anymore: if the TAM needs to have access
> to similar settings to heap ones, they have to explicitly define them.
>
> The 2nd patch file includes a new test module 'dummy_table_am' which
> implements a dummy table access method utilized to exercise TAM
> reloptions. This test module is strongly based on what we already have
> in 'dummy_index_am'. 'dummy_table_am' provides a complete example of TAM
> reloptions definition.
>
> This work is directly derived from SadhuPrasad's patch here [2]. Others
> attempts were posted here [1] and here [3].
>
> [1] https://www.postgresql.org/message-id/flat/429fb58fa3218221bb17c7bf9e70e1aa6cfc6b5d.camel%40j-davis.com
> [2] https://www.postgresql.org/message-id/flat/CAFF0-CG4KZHdtYHMsonWiXNzj16gWZpduXAn8yF7pDDub+GQMg(at)mail(dot)gmail(dot)com
> [3] https://www.postgresql.org/message-id/flat/AMUA1wBBBxfc3tKRLLdU64rb.1.1683276279979.Hmail.wuhao%40hashdata.cn

Please find a new version including minor fixes: 'TAM' terms are
replaced by 'table AM'

--
Julien Tachoires