Array vs. Value Index for ARRAY_CONTAINS

Mobile Couchbase Lite
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1

Using Couchbase Lite Swift, suppose I have a document that looks like this, where clearedProjects is an array of UUID strings:

// Pseudocode:

Foo {
    "clearedProjects": [String]
}

To find all Foo documents that contain a certain value in clearedProjects, I run this:

SELECT Meta().id FROM `Foo` WHERE (ARRAY_CONTAINS(`clearedProjects`, "e45a4b6c-9c01-4819-9d38-4dc448149b79"))

If I want to speed up this query with an index, should I use a value index or an array index?

let idxValueConfig = ValueIndexConfiguration(["clearedProjects"])
let idxArrayConfig = ArrayIndexConfiguration("clearedProjects")

// Should I use `idxValueConfig` or `idxArrayConfig` in place of the XXX? -->
try fooCollection.createIndex(withName: "clearedProjectsIndex", config: XXX)

The docs for ArrayIndexConfiguration state that this type of index is specifically for UNNEST. Which type of index is best for using ARRAY_CONTAINS?

3

Check examples here you also need query to use UNNEST make it faster

If u need to use ARRAY_CONTAINS basically use idxValueConfig which index whole array as scalar. That can bolt index and may not able to do indexscan efficently it may have to do whole indexscan