Development Meeting - Virtual - 2021 Meeting 1

Dates

Friday August 20th (estimated time period 2 hrs) - ​3PM - 5PM UTC

Goals

The main aim is to begin thinking about current planned release of PostGIS 3.2.0 and major features to be attempted.

• wiki:PostGIS32 topics
• GSOC Gist building enhancements for PostgreSQL 14
• PostGIS 3.2 ticket triage
• Need for a postgis_c_api for projects like MobilityDB, h3_pg
• Real World data testing
• Vote: Should our master repo be master or main?

• Add your own … ?

Attendance

PostGIS people who will be there

​Put your name on the poll if you plan to attend

Venue

• ​PostGIS jitsi channel
• ​Etherpad

---

Meeting Notes

Welcome

• Paul Ramsey (Crunchy Data) … coordination towards release time in fall
• Mahmoud SAKR (MobilityDB project, Université Libre de Bruxelles) - Discussing the dependancy of MobilityDB on PostGIS
• Darafei Praliaskouski (Kontur) - XMeans and future of parallel things, H3 things and creation of extensions depending on main PostGIS
• Regina (self)
• Raúl Marín (self)
• Mohamed Bakli (MobilityDB)
• Brian M Hamlin - OSGeo Live DVD
• Bruce Rindahl (self) documentation
• Giuseppe Broccolo - give updates about improvements in GiST build (with Han)
• Han Wang - GiST with pre-sorting methods
• Vicky Vergara (pgRouting & OSGeoLive & MobilityDB)
• Maxime Schoemans (MobilityDB)
• Esteban Zimanyi (MobilityDB)
• Jignesh Shah (AWS) .. learning about PostGIS (More on managing multiple versions)
• Jeremy Schneider (AWS) — PostGIS build considerations
• Aliaksandr Kalenik (Kontur)

Agenda

• GSOC Gist building enhancements for PostgreSQL 14
• Need for a postgis_c_api for projects like MobilityDB, h3_pg
• PostGIS 3.2 ticket triage
• Real World data testing
• Vote: Should our master repo be master or main?

GIST Building GSOC Project

• Good PoC completed
• Uses Pg14 pre-sort hooks in GIST to speed index build
• Index build time is made much faster
• Query performance may be slightly degraded compared to old implementation w/o pre-sort
• Pre-sort changes low-level page composition a little bit deleteriously
• Need some feedback on query against real-world data sets
• Is the sort key length (32bit) the problem? (Maybe not? Datum size is 64bit on most hardware)
• Q: Do PgSQL implementations of presort also show a performance degredation in query?
• Some degradation is expected. check first: ​https://observablehq.com/@mourner/hilbert-curve-packing

postgis_c_api

• MobilityDB uses liblwgeom library since PostGIS ~2.3 but can't support 3.x as liblwgeom is not exported
• MobilityDB uses a lot of functions in geography and other analytical functions, not just serialize/deserialize/lwgeom
• LWGEOM is done because Spatialite needed the topology
• Q: Can we provide an example of a "dependent extension" that calls PostGIS functions directly?
• VVergara will continue examining the actual extent of dependency and we will revisit
• Q: Call out ​pgpointcloud example of non-binary extension dependency
• ​https://en.wikipedia.org/wiki/GPL_linking_exception#:~:text=A%20GPL%20linking%20exception%20modifies,GPL%20to%20the%20using%20program.

master or main

• master - PR, Regina +1, Giuseppe, MS, Darafei +0 BH +1,JeremyVicky -0
• main - BR, Regina -1, Darafei +1,Jignesh Vicky +0
• Don't care: RM, Darafei +1 MD for now, but plan should be to change to main

Real World Data Testing

• Regina setting up a testing infrastructure - WIP: ​https://git.osgeo.org/gitea/postgis/postgis-performance
• Real world data sets in the "real" folder
• Example: ​https://github.com/pramsey/geos-performance/

PostGIS 3.2 Ticket Triage

• ​https://trac.osgeo.org/postgis/query?status=assigned&status=new&status=reopened&milestone=PostGIS+3.2.0&col=id&col=summary&col=status&col=owner&col=type&col=priority&col=milestone&order=priority

Alpha Release

Dependent on

• Han's GIST sort merge
• KMeans merge
• Boundary merge
• Paul's three feature tickets
• Paul's crasher tickets
• Sandro's cleanup of topology tickets and feature completion
• Upgrade changes (Regina)
• Address standardizer (Regina)

Target date?

• August 34th

Next Meeting?

• Maybe pre-release 3.2?
• For sure mid-winter (Jan/Feb?) + 1