I have been gathering some statistics about each major PostgreSQL release. Here is the update for this year:

  PostgreSQL 15 (2022) PostgreSQL 14 (2021) PostgreSQL 13 (2020) PostgreSQL 12 (2019)
changes listed in release notes 189 229 183 197
commits 2472 2702 2233 2429
contributors listed in release notes 412 415 380 410
total files 6114 5951 5688 5558
SLOC 1,077,633 1,045,222 1,024,657 990,405
files changed 3872 3764 3503 3429

Looking at these figures, it seems that the capacity of the PostgreSQL development team is somehow fixed. Now, one could think that this is a problem and that we might want to grow more. On the other hand, I have done similar analyses many times over the years, and the upshot was similar, and yet PostgreSQL continues to grow in use and popularity, so maybe it’s not all wrong.

One thing to note is that we are also adding code (files and lines) at a constant rate, which could increase the general maintenance cost in the long run, which could be a problem if we have a team with a non-growing capacity. So any efforts that facilitate code maintenance, including refactoring, deleting unused code and features, updating tooling, improving test performance, and modernizing the build system, continue to be necessary. Of course, if you think about it, this is already factored into these figures: If the code base is growing every year, yet we continue to produce new things at a constant rate while maintaining the existing code, the effective output of the team is also growing over time.

Details on how the numbers were derived:

(in each case, as of REL_15_0 tag, and analogously for other releases)

  • changes listed in release notes: grep '<listitem>' doc/src/sgml/release-15.sgml | wc -l (This possibly counts the “major items” at the top double, but it’s close enough.)

  • commits: git log --oneline REL_14_STABLE..REL_15_0 | wc -l

  • contributors listed in release notes: grep '<member>' doc/src/sgml/release-15.sgml | wc -l

  • files: git ls-files | wc -l

  • SLOC: sloccount --addlangall . (after git clean -fdx)

  • files changed: git diff REL_14_STABLE...REL_15_0 --name-only | wc -l