Re: [HACKERS] GSoC 2017: Foreign Key Arrays

Hi Mark,

On Mon, Jan 25, 2021, at 09:14, Joel Jacobson wrote:

I've continued testing by trying to make full use of this feature in the catalog-diff-tool I'm working on.

Today I became aware of a SQL feature that I must confess I've never used before,

that turned out to be useful in my tool, as I then wouldn't need to follow FKs

to do updates manually, but let the database do them automatically.

I'm talking about "ON CASCADE UPDATE", which I see is not supported in the patch.

In my tool, I could simplify the code for normal FKs by using ON CASCADE UPDATE,

but will continue to need my hand-written traverse-FKs-recursively code for Foreign Key Arrays.

I lived a long SQL life without ever needing ON CASCADE UPDATE,

so I would definitively vote for Foreign Key Arrays to be added even without support for this.

Would you say the patch is written in a way which would allow adding support for ON CASCADE UPDATE

later on mostly by adding code, or would it require a major rewrite?

I hesitated if I should share this with you, since I'm really grateful for this feature even without ON CASCADE UPDATE,

but since this was discovered when testing real-life scenario and not some hypothetical example,

I felt it should be noted that I stumbled upon this during testing.

Again, thank you so much for working on this.

/Joel