How to Build an Effective MongoDB Index Strategy

Those who use MongoDB on a regular basis to gather and store large amounts of data will find its ability to create indexes is a vital feature that ensures speed and efficiency. Without indexes, MongoDB will automatically scan all the information in its collection every time a search is performed. The process not only slows computer function as the system but is also time consuming as the user has to wait for the program to go through thousands or even tens of thousands of files to find relevant information. However, with indexes one can select only certain relevant portions of a folder or database for scanning. Furthermore, creating multiple small indexes make it possible to keep more indexed data in memory than would have been possible otherwise. Using multiple indexes, one can not only easily find information but also display it clearly in a variety of formats using visualization technologies like Kibana. At the same time, an individual or company using MongoDB to collect and store information should be aware that it is important to get the “indexing balance” just right. Over-indexing can cause the system to crash as it attempts to manage too many separate indexes; at the same time, under-indexing will make it hard to find all the important information on any given topic with ease.

Index Options

MongoDB offers a number of indexing options to make it easy for any user to choose the number and type of indexes that best meets his or her needs. The single field index system, which is the basic, most commonly used index type, enables one to create a user-defined ascending/descending index in a single document field. The order of the index does not impact search results as MongoDB can search the index in any direction.

The compound index system, as the name implies, enables one to search multiple fields. Unlike the single index, the compound index does take the order of the fields listed into account when doing a search. The index will need to be in just the right order to provide fast, fully accurate results.

The multikey index is specifically made for arrays and enables a user to create an index for every single element in an array.

MongoDB’s two geospatial index types are particularly handy for those who work with geospatial coordinate data while the text indexes are for anyone who needs to search string content in a collection.

Hashed indexes calculate the value of a particular field and are used to support equality matches, not range-based searches.

Indexing Considerations

There are several factors to take into account when deciding how many indexes to build and what data to include in any particular index set. One important point to consider is free memory as data indexes can impact both system memory and performance. Small indexes are naturally faster to create and easier to use than large ones. Data that is subdivided into small portions provides one with an accurate look at information subsets that may need attention; even so, those who want to see a bird’s eye view of all the data will need to either create one large index or be sure to select all the relevant smaller indexes when conducting a search.

Another point along the same lines that one will need to consider when choosing index types and sizes is the ratio of reads to writes that a particular set of data has. If data is continually added to a particular index, it can become quite large and time-consuming to search through. What is more, the larger an index is, the longer it will take to update it. In fact, when an index is being built or updated in a collection, that collection cannot be read until the building is complete unless the user opts to build the index in the background.

Indexing Strategy

It is important to create an indexing strategy before getting started. A good strategy should note which information is most frequently accessed, how that information would be best organized for ease of access, how often a particular index would be updated and how much room there is on a hard drive to accommodate a certain amount of information. Try out various indexing options to see which one would be the most efficient choice for any given set of information. Those who have created indexes in the past will want to check these to ensure they are as accurate and efficient as they should be. Once a user has a strategy in place for creating an index system, it’s time to get to work. One particularly efficient way to create an easy to use index system is to create indexes that support common queries. To do this, one will simply need to query certain information from MongoDB and then create an index based on the information that is given in the query results. If the query is general, one can create additional smaller indexes based on narrow search guidelines in order to see only certain query results as needed.

MongoDB is an efficient system that offers far more search and index building options than MySQL. Because MongoDB is document-based, it makes it possible for users to store extremely large amounts of data and then search through this data with ease in order to find information on any particular topic. What is more, MongoDB offers an array of index building tools not found in other, similar programs. As one continues using MongoDB and adapting the program’s index-building options to suit his or her needs, the program will continually provide a steady stream of important information that can offer accurate guidance when making business decisions. One can sort data based on any one of a number of options, including geographic location, number of customers, customer gender, age and/or marital status and much more. MongoDB is also extremely useful for reputation management as a business can not only store but also sort through user reviews, social shares, and comments to see what potential customers are saying about the company and its products and/or services. The ability to categorize vital information while excluding other information that is not relevant to one’s particular query is a vital one for any business or entrepreneur in any industry and learning how to use MongoDB’s multifaceted indexing system will not only enable a company to save time but also become both more efficient and more profitable. Here at ObjectRocket we have decades of expertise with MongoDB as a service, so feel free to contact us for your MongoDB needs.

Read more in-depth information about MongoDB indexes from our blogs:

5+1 Considerations for using $indexStats to find unused indexes in MongoDB

Are Index Issues Slowing your MongoDB Instance Down?