Re: Wrong usage of RelationNeedsWAL

Hi,

On 2021-01-13 16:07:05 +0900, Kyotaro Horiguchi wrote:
> Commit c6b92041d3 changed the definition of RelationNeedsWAL().
>
> -#define RelationNeedsWAL(relation) \
> - ((relation)->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT)
> +#define RelationNeedsWAL(relation) \
> + ((relation)->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT && \
> + (XLogIsNeeded() || \
> + (relation->rd_createSubid == InvalidSubTransactionId && \
> + relation->rd_firstRelfilenodeSubid == InvalidSubTransactionId)))
>
> On the other hand I found this usage.
>
> plancat.c:128 get_relation_info()
> > /* Temporary and unlogged relations are inaccessible during recovery. */
> > if (!RelationNeedsWAL(relation) && RecoveryInProgress())
> > ereport(ERROR,
> > (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> > errmsg("cannot access temporary or unlogged relations during recovery")));
>
> It works as expected accidentally, but the meaning is off.
> WAL-skipping optmization is irrelevant to the condition for the error.
>
> I found five misues in the tree. Please find the attached.

Noah?

Greetings,

Andres Freund