Partial index and exists clause

Working with Data
,
1

I have a partial index as follows

{
    "$and" : [
        {
            "field1" : {
                "$exists" : true
            }
        },
        {
            "field2" : {
                "$exists" : true
            }
        }
    ]
}

will query like
{ $and : [{ "field1" : { "$ne" : null } }, { "field2" : { "$ne" : null } }] }
use above index?
Also
{$and : [{"field1" : {"$exists" : true}}, {"field2" : {"$exists" : true}}]}
use above index?

2

Hello @Mayur_Thakare, Welcome to the MongoDB community forum,

Your question is not clear, I assume you have below the partial index and your provided queries should use the index.

db.collection.createIndex(
  { "field1": 1, "field2": 1 }, 
  { 
    partialFilterExpression: { 
      "$and" : [
        { "field1" : { "$exists" : true } }, 
        { "field2" : { "$exists" : true } }
      ] 
    } 
  }
)

Yes, it will use the index, and you can check by yourself using explain() command in your query,