Re: Inconsistent Behavior in JSONB Numeric Array Deletion

On Jun 11, 2025, at 16:03, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> The proposed behavior of the operator you want to add would be
> inconsistent with the existing integer subtraction operator, because
> the former would remove by value and the latter removes by index.

Bear in mind that `-` currently does both. Of the three current variants, the first two delete from an array by value:

* jsonb - text: Deletes a key (and its value) from a JSON object, or matching string value(s) from a JSON array.

* jsonb - text[] → jsonb: Deletes all matching keys or array elements from the left operand.

* jsonb - integer → jsonb: Deletes the array element with specified index (negative integers count from the end). Throws an error if JSON value is not an array.

Before I went and looked it up, I was also thinking this could use a different operator. But it’s already a bit overloaded, alas. So I could see the new behavior being:

* jsonb - jsonb → jsonb: Deletes the array element with specified value. Throws an error if JSON value is not an array.

> Now, none of that means that we couldn't define -(jsonb,jsonb) in the
> manner you propose. But that's just a feature idea, not an
> inconsistency.

Agreed. One might also think of it as a “gap to fill”, but it’s a new behavior. In any event, whether the feature uses `-` is a point we can resolve by consensus, given a patch that implements the feature.

Best,

David