In my collection I have an array like with exactly two values [a, b]
I want to create unique index on this array so that these excat two values will not repeat again.
For normal fields I can do something like this
User._ensureIndex('user_id', {unique: 1});
but when I try the same for array property it is showing error? Any help?
I’m creating index so that when I query using $in: [val1, val2] it will be fast or am I wrong that $in doesn’t support index?