Re: Questions about support function and abbreviate

2021-06-12 Thread Giuseppe Broccolo
Hi Han, Darafei already provided a good answer to your question, I will add just a few things with the hope of making things more clear for your use case. SortSupport implementation in PostgreSQL allows to make comparisons at binary level in a dedicated region of memory where data can be quickly

Re: Questions about support function and abbreviate

2021-06-12 Thread Han Wang
Hi Darafei, Thanks for your reply. However, I still don't get the full picture of this. Let me make my question more clear. First of all, in the *`gistproc.c `* of Postgres, it shows that the `abbreviate`

Re: Questions about support function and abbreviate

2021-06-11 Thread Komяpa
Hello, the abbrev_converter is applied whenever it is defined. The values are sorted using the abbreviated comparator first using the shortened version, and if there is a tie the system asks the real full comparator to resolve it. This article seems to be rather comprehensive: https://brandur.org

Questions about support function and abbreviate

2021-06-11 Thread Han Wang
Hi all, I am trying to implement a sort support function for geometry data types in PostGIS with the new feature `SortSupport`. However, I have a question about this. I think it is hardly to apply a sort support function to a complex data type without the `abbrev_converter` to simply the data str