Re: Bug in new buffer freelist code

Tom Lane wrote:
> Jan Wieck <JanWieck(at)Yahoo(dot)com> writes:
>> It seems to me that buffers that are thrown away via
>> StrategyInvalidateBuffer() do not get their relnode and blocknum cleaned
>> out.
>
> Mmmm. They definitely should be; if you look at the prior version of
> buf_table.c, BufTableDelete did this:
>
> /*
> * Clear the buffer's tag. This doesn't matter for the hash table,
> * since the buffer is already removed from it, but it ensures that
> * sequential searches through the buffer table won't think the buffer
> * is still valid for its old page.
> */
> buf->tag.rnode.relNode = InvalidOid;
> buf->tag.rnode.tblNode = InvalidOid;
>
> I see you removed that from the current version, but the equivalent
> thing needs to be done someplace. Is StrategyInvalidateBuffer the
> right place?

Yeah, looks like ... but I actually want to have a clean reproduction of
the error before I attempt to fix it. Will look at it deeper.

>
> BTW, it kinda looks like the BM_DELETED flag bit is useless now?

I think so, together with the BM_FREE which was redundant anyway.

Jan

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