do not use $ne operator

[gabzim]

In large collections, the $ne operator is very inefficient and can make queries slow. (https://docs.mongodb.com/manual/reference/operator/query/ne/ last paragraph).

I recently had to investigate performance troubles we're having in one of our largest collections and it's due to the use of this plugin. What I'd suggest is maybe always keeping deleted as false and then doing {$eq: false} to retrieve active documents.

[tcstory]

assume I had the following documents, the documents were producted before I use mongoose-delete plugin,

{_id: 'xx', name:1},
{_id: 'xx', name:2},
{_id: 'xx', name:3},

and now I start to use this plugin, because it use $ne operator, so it will treat these documents as undeleted, this is what I need. but if it use $eq operator, I have to add deleted: false to every documents.

[gabzim]

True, but if your collection has 1,000,000 docs instead of 3, a query that does not filter them out by an index will timeout. And this can get unpredictable as it will happen in some collections and it won't in others.

[bdelville]

Until proposing a pull request, a quick fix is:
countWithDeleted(Object.assign({deleted: false}, query));

That supposed that "deleted" always exist, which is the case in my database

[bdelville]

It is in pull request

[dsanel]

This type of changes can affect existing users and I really try to keep back compatibility with older versions. This is the main reason why I introduce new option use$neOperator so you can override default behavior (default is {use$neOperator: true}).

This new option will cover both scenarios.

https://github.com/dsanel/mongoose-delete/blob/master/test/index.js#L1598-L1654

Hope this will help @gabzim? ;)

[simplenotezy]

FYI I just tried doing a comparison, and inside a collection of +1mn documents, and I didn't see any noticeable difference.

Am I missing something?

Using deleted: {$ne: true}

Using deleted: false