PSA: Upcoming changes in Postgres 18

[yrashk]

Fellow @pgedc/members extension developers, the upcoming release packs a few breaking changes.

Let's start identifying them to help with upgrades later this year.

What I found so far:

• ExecutorRun drops the excecute_once parameter 3eea7a0c97e94f9570af87317ce3f6a41eb62768
• pqsignal no longer returns the previous signal handler d4a43b283751b23d32bbfa1ecc2cad2d16e3dde9
• returningList in statements is replaced with returningClause
• Possible new interactions in the ordering of enclosure of SPI context and transaction with regards to memory context (pending further research) – possibly 40126ac68f2ff96351cd6071350eb2d5cbd50145 but not quite sure. Likely a minor consequence, but helped me to find a subtly wrong ordering.

Please add yours as you find them so we can compile an upgrade guide timely!

[danolivo]

My favourite change for now is increase of the Var structure - added the VarReturningType field.

[yrashk]

I am assuming this means it's not a breaking change, but rather an improvement opportunity?

[danolivo]

It is an opportunity each time ;). But generating paths we need to consider such changes all the time to not provide incorrect alternative.

[danolivo]

One more change we should remember in v.18: the SetOpPath logic: at least, its structure has been changed. But also the internals of the operator also shifted and may impact some extensions that offer alternative paths.