Re: currtid_byreloid and currtid_byrelname

"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
>> In utils/adt/tid.c, there's two mysterious functions with no comments,
>> and no-one calling them inside backend code AFAICT: currtid_byreloid and
>> currtid_byrelname. What do they do/did?
>
> IIRC, the ODBC driver uses them, or once did, to deal with
> concurrent-update situations --- it wants to be able to find the
> currently committed version of a row it saw as valid earlier in the
> transaction. I think it's sort of a client-side version of the
> EvalPlanQual stuff. Hiroshi probably remembers more.

It could be using currtid_byreloid:

List of functions
Schema | Name | Result data type | Argument data types | Owner | Language | Source code | Description
------------+---------+------------------+---------------------+-------+----------+------------------+-----------------------
pg_catalog | currtid | tid | oid, tid | stark | internal | currtid_byreloid | latest tid of a tuple
(1 row)

But how would it use currtid_byrelname?

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com