Web lists-archives.com

Re: reftable [v6]: new ref storage format

On Tue, Aug 8, 2017 at 4:34 PM, Junio C Hamano <gitster@xxxxxxxxx> wrote:
> Shawn Pearce <spearce@xxxxxxxxxxx> writes:
>> Given that the index can now also be multi-level, I don't expect to
>> see a 2G index. A 2G index forces the reader to load the entire 2G to
>> take advantage of the restart table. It may be more efficient for such
>> a reader to have had the writer make a mutli-level index, instead of a
>> single monster index block. And so perhaps the writer shouldn't make a
>> 2G index block that she is forced to buffer. :)
> Ah, OK, then it is sensible to have all table blocks to have the
> same format, and restart at the beginning to help readers would be a
> fine choice.  For the same "let's make them as consistent" sake, I
> am tempted to suggest that we lift "the index block can be 2G" and
> have it also be within uint_24(), perhaps?  Otherwise the readers
> would have to read (or mmap) the whole 2G.

Gah. I just finished moving the restart table back to the end of the block. :)

However, I think I can agree with the index fitting into the uint24
size of 15M, and asking writers making an index that exceeds that to
use multi-level indexing.