Re: Fix typo about generate_gather_paths

On 12/9/20 3:21 AM, Hou, Zhijie wrote:
> Hi
> 
> Since ba3e76c,
> the optimizer call generate_useful_gather_paths instead of generate_gather_paths() outside.
> 
> But I noticed that some comment still talking about generate_gather_paths not generate_useful_gather_paths.
> I think we should fix these comment, and I try to replace these " generate_gather_paths " with " generate_useful_gather_paths "
> 

Thanks. I started looking at this a bit more closely, and I think most 
of the changes are fine - the code was changed to call a different 
function, but the comments still reference generate_gather_paths().

The one exception seems to be create_ordered_paths(), because that 
comment also makes statements about what generate_gather_pathes is 
doing. And some of it does not apply to generate_useful_gather_paths.
For example it says it generates order-preserving Gather Merge paths, 
but generate_useful_gather_paths also generates paths with sorts (which 
are clearly not order-preserving).

So I think this comment will need a bit more work to update ...


regards

-- 
Tomas Vondra
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