Re: [PATCH 05/14] Add a new relmapper.c function RelationMapFilenodeToOid that acts as a reverse of RelationMapOidToFilenode

Hi,

On 2012-11-16 13:44:45 +0900, Michael Paquier wrote:
> This patch looks OK.
>
> I got 3 comments:
> 1) Why changing the OID of pg_class_tblspc_relfilenode_index from 3171 to
> 3455? It does not look necessary.

Its a mismerge and should have happened in "Add a new RELFILENODE
syscache to fetch a pg_class entry via (reltablespace, relfilenode)" but
it seems I squashed the wrong two commits.
I had originally used 3171 but that since got used up for lo_tell64...

> 2) You should perhaps change the header of RelationMapFilenodeToOid so as
> not mentionning it as the opposite operation of RelationMapOidToFilenode
> but as an operation that looks for the OID of a relation based on its
> relfilenode. Both functions are opposite but independent.

I described it as the opposite because RelationMapOidToFilenode is the
relmappers stated goal and RelationMapFilenodeToOid is just some
side-business.

> 3) Both functions are doing similar operations. Could it be possible
> to wrap them in the same central function?

I don't really see how without making both quite a bit more
complicated. The amount of if's needed seems to be too large to me.

Thanks,

Andres Freund

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