Re: Batch update of indexes

On 20 January 2016 at 14:55, Konstantin Knizhnik <k(dot)knizhnik(at)postgrespro(dot)ru>
wrote:

> Hi,
>
> Hi, I glad to see that you interested in that too.
>> I think this is a good feature and I think it will be very useful to have.
>> I have already mentioned some related problems and possible improvements
>> in my presentation.
>>
>> http://www.slideshare.net/AnastasiaLubennikova/indexes-dont-mean-slow-inserts
>> Last two slides concern to this thread. Briefly, I've suggested to think
>> about insertion buffer. Something very similar to it is already implemented
>> in BRIN. It does not index last data from heap, while the number of last
>> pages is less than pages_per_block.
>>
>
> Do you mean GIN-like usage of insertion buffer (here it is called "pending
> list")?
> So that we have to combine search in the main tree and in the insert
> buffer?
> Actually this is what I want to avoided (because at least in case of GIN
> pending list cause significant degrade of performance,
> while up-to-date state of full text index is rarely required).

Degrade in performance is because scan of pending list is O(N).

If we did the same thing for monotonic inserts into a btree, the
performance of ruling out any contents in the pending list would be O(1),
so it is more feasible than you say.

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