Re: [HACKERS] [PATCH] Generic type subscripting

> On 20 September 2017 at 17:19, Arthur Zakirov <a.zakirov@postgrespro.ru> wrote:

> As a conclusion:

> * additional field are needed to pg_type for *_fetch and *_assign functions to solve dependency problem

One last thing that I need to clarify. Initially there was an idea to minimize

changes in `pg_type` - that's why I added only one column there that contains an

OID of main subscripting function (and everything else you should find out

inside it). But I have no objections about adding more columns if everyone is

ok with that. Basically pros and cons (marked as + and -):

one new column in `pg_type`:

* less intrusive (+)

* it's neccessary to make a dependency record between subscripting functions

  explicitly (-)

three new columns in `pg_type`:

* more intrusive (-)

* we can create a dependency record between subscripting functions

  simultaneously with a custom type creation (+)

* custom subscripting code does not need to resolve `fetch` and `assign`

  functions (+)