null VS bitmap

Use-case: working on PATCH requests, the body may or may not contain nullable values. I am using guregu/null and I can't use a pointer because if the json contains "null" as a value, the pointer will be set to nil in the struct, instead of a value representing the presence of null. In short I can't differentiate the absence of the field in the request from the presence of the field with a null value.

https://github.com/guregu/null is an awesome package implementing most SQL scanner Interfaces plus JSON

There’s also this: https://github.com/guregu/null

Unfortunately in Go, switching to *bool makes the api a little more awkward to use since users that need to set true or false have to define a local variable then use a pointer to that. Another option would be something like null, but that adds a dependency to your currently-dependency-free project. If anyone has a better solution to this pattern, I'd love to hear it.

Good question, I think there's many different lessons. To your point about bitmasks, you can imagine that each component (i.e. column) has an array of data and a large bitmap that identifies whether a component is present or not. Had to build a SIMD implementation so you can do and, and not, or and xor operations on millions of components within reasonable amount of time. Interestingly enough, you still need a hashmap or b+tree in case you want to retrieve a component by it's ID instead of an index, but the rest of things can be modeled with bitmap indexes.