To debug the query in Robomongo! - Donnell.Rippin commented on June 8th 19 at 14:59įind more questions by tags Node. select('url category tags public owner')Ĥ. Request (if mongoose, I don't know what you have there): Ts: 'String', // here you have bonded with tagsģ. Add a simple text field with tags and leave the field with arrays. I am looking for more information about how the query optimizer evaluates candidate plans. They added $lookup relatively recently, so it may not work very optimally.ġ. The MongoDB query optimizer processes queries and chooses the most efficient query plan for a query given the available indexes This is an excerpt from MongoDB documentation.

In theory, the optimizer should track it, but that it is implemented in practice I can't tell you. $lookup you performed before $limit, this means that the pipeline must first connect all the found records, and then perform the restriction. It works fine with find() and lookup is not needed. If I understand correctly, you are using mongoose. I don't quite understand why you are doing it all through aggregation. In fact, an index is created url_1_public_1_tags_1_catalog_1, ignoring another sorting tags The query works well when I need to make a selection similar records sorted by field tags in the case when documents with the same tags a bit, the query runs relatively quickly, but if such documents thousands, is already running around 1.5-2sec. Tags:, // mostly contains from 5 to 12 values Here is an example of a completed document There are documents, list only the most important fields If(dataSet.result != null & all, can tell me how can optimize the query below, or perhaps even revise the structure of the document. Now let’s use all 50 million entries to build a daily report, counting how many events were generated in a day, including the minimum, the maximum and the average value for that particular day. 'created_on' : ISODate('T06:08:47.835Z'),īeside the default primary key “_id” index, we also created one for the “created_on” field, so these are all our indexes: The optimizer does not consider whether the index helps with sorting. This is how a time-event entry looks like: This time, we will make use of all that data to fuel our aggregation tests. In my previous post, I demonstrated how fast you can insert 50 millions time-event entries with MongoDB. Use hint() to support performance testing, or on some queries where you must select a field or field included in several indexes. Follow having a tool that can automatically detect JPA and Hibernate performance issues. In most cases the query optimizer selects the optimal index for a specific operation however, you can force MongoDB to use a specific index using the hint() method.

Mongo db optimizer