On Fri, May 23, 2025 at 5:03 PM Bruce Momjian <[email protected]> wrote: > I was able to squeeze in this detail in the attached, applied patch.
I noticed that Crunchy Data had a blog post about the skip scan, where the author got tripped up by the description of skip scan that current appears in the release notes. See: https://www.crunchydata.com/blog/get-excited-about-postgres-18 The blog post incorrectly says "Note that this optimization only works for queries which use the = operator, so it will not work with inequalities or ranges". This is incorrect; skip scan works perfectly fine with inequality operators. I'm sure that this confusion arose because of the wording from the release notes. Adding to the confusion, Crunchy also had a Tweet about skip scan that used an inequality operator (which will work correctly): https://x.com/crunchydata/status/1965751871848468499 I'm sure that this was due to the release note description, since there was some discussion of it on a LinkedIn post that promoted the blog post. In light of all this, I propose that we change the current feature description, from: "This allows multi-column btree indexes to be used by queries that only equality-reference the second or later indexed columns." to: "This allows multi-column btree indexes to be used by queries that only specify conditions on the second or later indexed columns." -- Peter Geoghegan
