Euphorichuman
`nil` or empty list?
I’m managing my Postgres database with Ecto and I have come across a situation: In some of the fields for some of my records, I save empty values: For this case, it would be an empty list [].
Empty list or nil, which is better or more efficient?
Marked As Solved
eksperimental
empty list.
See this PR that was an optimization to MapSet.
https://github.com/elixir-lang/elixir/pull/5954
Also Liked
dorgan
Tangential fun fact: In Erlang, the empty list [] is internally called nil, and it has it’s own position in the erlang term ordering 
benwilson512
I would first and foremost prioritize clarity, then performance here, since the difference is negligible in most cases. If you have a column that can either have a value, or no value, then use nil to mean “no value”. If you have a collection of things and that collection can be empty, then use an [].
al2o3cr
If you’ve got a JSONB column or a nullable array column, using nil is going to cause the usual SQL NULL behaviors while using [] will not.
Last Post!
al2o3cr
If you’ve got a JSONB column or a nullable array column, using nil is going to cause the usual SQL NULL behaviors while using [] will not.
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