Re: [PATCH] Largeobject access controls

KaiGai Kohei <kaigai(at)ak(dot)jp(dot)nec(dot)com> wrote:

> The pg_largeobject system catalog is reworked to manage its metadata.
>
> CATALOG(pg_largeobject,2613)
> {
> Oid loowner; /* OID of the owner */
> Oid lochunk; /* OID of the data chunks */
> aclitem loacl[1]; /* access permissions */
> } FormData_pg_largeobject;
>
> Actual data chunks are stored in the toast relation of pg_largeobject,
> and its chunk_id is stored in the pg_largeobject.lochunk.

A bit acrobatic, but insteresting idea.

I have some random comments:

* Do you measure performance of the new LO implementation?
AFAIK, Users expect performance benefits to LO; TOASTed
bytea slows down when the size of data is 100KB or greater
even if they don't use random seeks.

* We might take care of DROP ROLE and REASSIGN/DROP OWNED.
Or, we might have large object without owner.
It might require full-scanning of pg_largeobject table,
but we can accept it because the size of pg_largeobject
will be smaller; we have actual data out of the table.

* Don't we also need "ALTER LARGE OBJECT <oid> OWNER TO <user>"
for consistency?

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center