I have the following data structure which has an indexed field as an array of strings.

<QUERY IN ATTACHMENT>

The below query was working fine in mongodb 2.4.

{ "docKey" : { "$in" : ["M06001XXXX45378CED", "M06001ZZZ45378CED"] }, "serviceGroupCode.estimateCategories.code" : "SEC02" }, { "serviceGroupCode.estimateCategories.$" : 1 }

But after upgrading to mongo db 2.6, this query is failing.
The above query works fine only if the $in operation consists of the first array element. Otherwise, it results is projection failure.

I initially thought that the indexing would have failed for other array elements but they work fine when queried alone without the $ projection.

I could not find any documentation that touches impact to these operation. Hence it would be of great help if this issue can be looked upon and a resolution can be provided at the earliest.

Thank You,
Sulbigar S