Thread: Possibilities on code change to implement pseudodatatypes

Greetings

I understand the complexity of implementing a pseudo data type when 

passing it over parameters, or using it when creating an object.

vide: git grep pseudo | egrep -v -e "po|out|sgml|sql" | more

My initial problem was saving history (for backup to be used during troubleshoot analysis) of plan changing and so on..  of the pg_statistic table/object.

I was surprised - in a good way - to observe so much effort when handling it for that specific purpose. I started to wonder if/when I want to create an object of other pseudatatypes or pass it through a function parameter that the same level of effort during code implementation would be the same.

I understand this would be much more a code architecture discretion rather than a punctual question.

I have posted in pgsql-admin a question which is "simple problem" when creating a table using anyarray and indeed the problem is simple - the solution might not be.

What folks, more experienced in this subject, would recommend as a starting point to achieve that objective?

 

Kind regards,

Bazana Schmidt, Vinícius

PS.: apologize in advance for the HTML email.

On Mon, Sep 30, 2024 at 9:01 AM Vinícius Abrahão <vinnix.bsd@gmail.com> wrote:

Greetings

I understand the complexity of implementing a pseudo data type when 

passing it over parameters, or using it when creating an object.

vide: git grep pseudo | egrep -v -e "po|out|sgml|sql" | more

My initial problem was saving history (for backup to be used during troubleshoot analysis) of plan changing and so on..  of the pg_statistic table/object.

I was surprised - in a good way - to observe so much effort when handling it for that specific purpose. I started to wonder if/when I want to create an object of other pseudatatypes or pass it through a function parameter that the same level of effort during code implementation would be the same.

I understand this would be much more a code architecture discretion rather than a punctual question.

I have posted in pgsql-admin a question which is "simple problem" when creating a table using anyarray and indeed the problem is simple - the solution might not be.

What folks, more experienced in this subject, would recommend as a starting point to achieve that objective?

 

Kind regards,

Bazana Schmidt, Vinícius

PS.: apologize in advance for the HTML email.

Complementing -

Under this optics below:

[vinnix@vesuvio postgres]$ git grep CheckAttributeType
src/backend/catalog/heap.c: *           flags controls which datatypes are allowed, cf CheckAttributeType.
src/backend/catalog/heap.c:             CheckAttributeType(NameStr(TupleDescAttr(tupdesc, i)->attname),
src/backend/catalog/heap.c: *           CheckAttributeType
src/backend/catalog/heap.c:CheckAttributeType(const char *attname,
src/backend/catalog/heap.c:             CheckAttributeType(attname, getBaseType(atttypid), attcollation,
src/backend/catalog/heap.c:                     CheckAttributeType(NameStr(attr->attname),
src/backend/catalog/heap.c:             CheckAttributeType(attname, get_range_subtype(atttypid),
src/backend/catalog/heap.c:             CheckAttributeType(attname, att_typelem, attcollation,
src/backend/catalog/index.c:                    CheckAttributeType(NameStr(to->attname),
src/backend/commands/tablecmds.c:       CheckAttributeType(NameStr(attribute->attname), attribute->atttypid, attribute->attcollation,
src/backend/commands/tablecmds.c:       CheckAttributeType(colName, targettype, targetcollid,
src/backend/commands/tablecmds.c:                       CheckAttributeType(partattname,
src/include/catalog/heap.h:/* flag bits for CheckAttributeType/CheckAttributeNamesTypes */
src/include/catalog/heap.h:extern void CheckAttributeType(const char *attname,

and this line:

https://github.com/postgres/postgres/blob/master/src/backend/catalog/heap.c#L562

 

  if (att_typtype == TYPTYPE_PSEUDO)

  {

  /*

  * We disallow pseudo-type columns, with the exception of ANYARRAY,"  <<==

What WE are missing? WHY? How could we make this state true for creating table commands?

I will try to find time to keep researching about it - if you folks have any insights please let me know.