On 04/01/2019 21:26, Andrey Borodin wrote:
3 янв. 2019 г., в 23:47, Andrey Borodin <x4...@yandex-team.ru>
написал(а):
* Bitmapset stores 32 bit signed integers, but BlockNumber is
unsigned. So this will fail with an index larger than 2^31
blocks. That's perhaps academical, I don't think anyone will try
to create a 16 TB GiST index any time soon. But it feels wrong to
introduce an arbitrary limitation like that.
Looks like bitmapset is unsuitable for collecting block numbers due
to the interface. Let's just create custom container for this? Or
there is one other option: for each block number throw away sign
bit and consider page potentially internal and potentially empty
leaf if (blkno & 0x7FFFFFF) is in bitmapset. And then we will have
to create at least one 17Tb GiST to check it actually works.
Heikki, how do you think, is implementing our own radix tree for this
is viable solution? I've written working implementation with 4-level
statically typed tree. If we follow this route, probably, there must
be tests for this data structure.
Yeah, seems reasonable.
- Heikki
