Re: Stream bitmaps

Heikki, are you going to submit this for 8.4?

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Heikki Linnakangas wrote:
> Hi all,
> 
> I'd like to see the indexam API changes needed by the bitmap indexam to 
> be committed soon. Has anyone looked at the proposed API in the latest 
> patch? Any thoughts?
> 
> I'm quite happy with it myself, with a few reservations:
> 
> - All the getbitmap implementations except the new bitmap indexam are 
> just boilerplate. How about making getbitmap-function optional, and 
> having a generic implementation that fills in a hash bitmap using the 
> traditional getnext function?
> 
> - getbitmap is passed an existing bitmap as argument, and the 
> implementation needs to OR the existing bitmap with new tuples. How 
> about AND? An indexam could be smart about ANDing with an existing 
> bitmap, for example skipping to the first set bit in the existing bitmap 
> and starting the scan from there.
> 
> - I'd like to have support to return candidate matches with both 
> getbitmap and getnext. A simple flag per page of results would be enough 
> for getbitmap, I think.
> 
> - StreamBitmap and HashBitmap are separate node types, but OpStream is 
> not. opaque-field in the StreamBitmap struct is not really that opaque, 
> it needs to be a StreamNode. I drew a UML sketch of what I think the 
> class-hierarchy is 
> (http://community.enterprisedb.com/streambitmaps.png). This is 
> object-oriented programming, we're just implementing classes and 
> inheritance with structs and function pointers. The current patch mixes 
> different techniques, and that needs to be cleaned up.
> 
> I'd like to see a separate patch that contains just the API changes. 
> Gavin, could you extract an API-only patch from the bitmap index patch? 
> I can work on it as well, but I don't want to step on your toes.
> 
> -- 
>    Heikki Linnakangas
>    EnterpriseDB   http://www.enterprisedb.com
> 
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