Google Summer of Code 2021

Introduction

So you are interested in becoming a Google Summer of Code student. What should you do to improve your chances of being selected? We recommend reading

• ​OSGeo's GSoC Recommendations for Students
• We currently have one project in mind listed below, with a mentor ready to help - refer to Idea 1 below. We are open to other ideas, but Idea 1 takes precedence since we already have a mentor for that.
• Join the ​PostGIS Developers list and describe your proposed project (or willingness to work on Idea 1 listed below). We will let you know if we think the project is worthwhile and doable within the allotted time you have.
• If you are looking for additional ideas, refer to our past GSOCS:
  • Google Summer Of Code 2019
  • Google Summer Of Code 2018
  • Google Summer Of Code 2013

Improving your chances

For most projects involving PostGIS you will eventually need the following:

• Know how to install PostgreSQL
• Know how to install PostGIS in PostgreSQL
• Know how to compile PostgreSQL code
• Know how to compile PostGIS code and run tests
• Some basic knowledge of git — at least how to do a git clone, git push, git pull and pull requests

While you can learn to do these things and ask questions, we would prefer students to know these before starting on a PostGIS project.

Idea 1: Augment PostGIS 3.2 with GIST support added to PG14

Expected outcome: Speed up GiST index building in PostGIS

Skills required: C or willing to learn, ability to compile PostgreSQL code, ability to compile PostGIS code, some familiarity with PostGIS / PostgreSQL is preferable

Mentors: Giuseppe Broccolo, Regina Obe

Difficulty: Medium

Student Test:

1. git clone PostGIS code from one of Git repos
2. git clone code from PostgreSQL git repo (master branch) -
3. Compile both and install PostGIS 3.2 (master branch) extension into PostgreSQL 14 dev database
4. Setup a public fork of PostGIS repo for your work and do the development work
5. Once ready submit a pull request to any of PostGIS repos

Additional detail:

Recently this patch <​https://commitfest.postgresql.org/29/2276/> which adds more infrastructure to the GiST has been included in PG14. It should speed up the build of a GiST index after some (fast) pre-sorting of the data which needs to be indexed. Some tests for the PG's internal type point (that uses Zsort as fast pre-sorting of the data) showed that the build is up to 5 times faster.

I'd like to study a possible implementation for PostGIS data types. Basically, it would require to add this support function <​https://github.com/glukhovn/postgres/blob/225a49161fae9388651373d4beb8dcba99059339/src/include/access/gist.h#L37> and this other one <​https://github.com/glukhovn/postgres/blob/225a49161fae9388651373d4beb8dcba99059339/src/include/access/gist.h#L38> in the operator classes which use the GiST infrastructure (e.g. this one <​https://github.com/postgis/postgis/blob/8b13c3e2f8366d902dbf516ec17de09ae84361f4/postgis/postgis.sql.in#L781> ).