CODEWITHSUNDEEP
mongodb
Martlark
Martlark

Reputation: 14581

inserting in mongo forEach continues for ever

I'm creating some fake documents by 'expanding' the existing documents by 20 times. But; the forEach loop never seems to end. Why?

db['COLLECTION'].find({}).forEach(function(doc){
    for( var x = 0; x < 20; x++ ) {
            delete doc['_id'];
            doc['Author'] = randArrayElement(names); /* chooses random name */
            doc['Description'] = buzzword(); /* makes something up*/

            db['COLLECTION'].insert(doc);
        }
    }
 )

Upvotes: 3

Views: 2813

Answers (1)

Salvador Dali
Salvador Dali

Reputation: 222531

I think you need to use snapshot here:

db['COLLECTION'].find().snapshot().forEach(function(doc){
  ...
})

I assume that this happens because write operations might result in a move of the document and snapshot fixes it:

The $snapshot operator prevents the cursor from returning a document more than once because an intervening write operation results in a move of the document.

If this will not help, then I have another idea that the newly created documents are picked up by the cursor. To overcome this I would create an array of all the documents, and then separately iterate them and do your 20 inserts for each one.

Upvotes: 5

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