"PCRE" ) version 8. This section explain how to use a regular expression in an array. js is a "batteries included" SQL query builder for Postgres, MSSQL, MySQL, MariaDB, SQLite3, Oracle, and Amazon Redshift designed to be flexible, portable, and fun to use. 41 with UTF-8 support. You can use forEach loop in day-to-day … Continue reading How to use forEach Loop in mongoDB to. MongoDB is a database which came into light around the mid-2000s. http://technotip. This is why Regex is better than string. Before MongoDB came up with the concept of text indexes, we would either model our data to support keyword searches or use regular expressions for implementing such search functionalities. In Meteor, that data layer is typically stored in MongoDB. Adding Document Validation Rules Using MongoDB Compass 1. This is a great way to kick-start your learning on schema design with the document data model. Mongodb now supports advanced full text searching, with many features. We’ll illustrate this by going through some examples of different MongoDB regex queries and how they can cause issues for your database. What is the best way (performance wise) to paginate results in MongoDB ? Especially when you also want to get the total number of results ? Project running with. StickerYou. Optional password-protection for one or more users. GitHub Gist: instantly share code, notes, and snippets. Regular Expression. Replace call result. You really need it where you can, to make matches at the "start" of the string where an index can be properly used. matches newline as well: x: Allow spaces and comments: J: Duplicate group names allowed. Mongo Shell. Learning MongoDB will show you how to install, configure, and secure MongoDB to meet the demands of modern enterprise data systems. BSON specifi. Observe the documents – it has some names which are in alphabetical order. Regex Space or Whitespace. In this Blog I'll tell you about How to replace Special Characters Using Regex in C#. Regular expressions are used for text searching and more advanced text manipulation. We’ll illustrate this by going through some examples of different MongoDB regex queries and how they can cause issues for your database. By using for forEach loop you can manipulate documents on your collection. However, using any of these approaches had its own limitations:. Validate Traditional Date Formats Problem You want to validate dates in the traditional formats mm/dd/yy, mm/dd/yyyy, dd/mm/yy, and dd/mm/yyyy. regex package. Last document has an extra field called age. MongoDB supports field, range query, and regular-expression searches. ATTRIBUTES pattern. Today we would like to introduce you to the new MongoDB Full Text Search and compare its capabilities and performance with simple regular expressions, which are currently state of the art for. Text Matching — Contains, Starts / Ends With — Regular Expression. After MongoDB Capped Collection, today we are going to see a new concept MongoDB Regular Expression for pattern maching. Forming a regular expression. * [PHPC-885] - Alphabetize Regex flags when instantiating from BSON * [PHPC-886] - Always recalculate field name length when encoding BSON * [PHPC-891] - BSON encoding should throw if PHP keys contain null bytes. I was busy writing a Node. 0, adds support for all the new shell methods and operations of MongoDB 4. MongoDB saves attribute names in each document, ofcourse this takes a lot of storage. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] For detailed information, consult the regular expressions tutorial. public class Car { public string Name; public List Colors; } this only works for plain list LINQ: var regex = new Regex("^Blue. Fields can vary from document to document. 12 - I have a curious case where depending on what syntax is used for a regex expression, proper indexes are used. It depends on libbson to generate and parse BSON documents, the native data format of MongoDB. MongoDB Regular Expression. MongoDB University offers a no-cost, web-based training course on data modeling. In this post, we’ll show you how to use MongoDB connection pooling on AWS Lambda using both Node. results matching "". class bson. 0: The flags argument is optional and defaults to an empty string. As a valued partner and proud supporter of MetaCPAN, StickerYou is happy to offer a 10% discount on all Custom Stickers, Business Labels, Roll Labels, Vinyl Lettering or Custom Decals. But I would have preferred the use of regular expressions since it can be used in much more cases (for exemple a. Introduction. Adding Document Validation Rules Using MongoDB Compass 1. This quick start gets you up to speed quickly with regular expressions. Python script to identify regex matches in all subdirs and write dict of matches to MongoDB Insert each key/value pair in the dictionary into a MongoDB collection. Updated for MongoDB 4. The regular expression in a programming language is a unique text string used for describing a search pattern. Trouble figuring out how to anchor a regex in a match (self. The official MongoDB container. $regex¶ $regex¶. 2 along with some useful improvements and bugfix. Validate Traditional Date Formats Problem You want to validate dates in the traditional formats mm/dd/yy, mm/dd/yyyy, dd/mm/yy, and dd/mm/yyyy. ; MongoDB uses Perl compatible regular expressions (i. Learn how to use Robo 3T with Azure Cosmos DB's API for MongoDB. shell regex. Regular expressions (regex) provide a way to match strings against a pattern and MongoDB comes with a regex engine built in. js driver for the database in your app. I have a db that list objects with ids, however I want to fetch a field named lets say a url but I want to get all the urls and also not just any url I want to get the ones that include some partial text and filter using that text and and give me all of those urls. Well, I’m going to try to explain about forEach loop which is very powerful for housekeeping sort of job in day-to-day activities. The objects attribute is actually a QuerySetManager, which creates and returns a new QuerySet object on access. The MongoDB $regex operator provides such a way to search a string after. To clarify, I’m looking for a decent regular expression to validate URLs that were entered as user input with. As for the performance. What is the best way (performance wise) to paginate results in MongoDB ? Especially when you also want to get the total number of results ? Project running with. Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. One bad regex query can impact the performance of your whole MongoDB instance. Fields in a MongoDB document can be indexed with primary and secondary indices. This table displays some examples of the syntax and structure of the queries you can use to request data from MongoDB. regex str (regular expression) Keep labels from axis for which re. The flexibility of unstructured storage, combined with robust querying and post processing functionality, make MongoDB a compelling solution for enterprise big data needs. Java Regular Expression Validate date example shows how to validate date using regex in Java. Here a tag can be located by just using a few letters of a word within a collection. Regular expressions (regex) provide a way to match strings against a pattern and MongoDB comes with a regex engine built in. shell regex. Regular expressions are a pattern matching technique provided by MongoDB as a feature that is used to search for a string within documents. Serialization. SQL to MongoDB Mapping Chart¶. Even with small datasets, it's not very efficient. I'm still leaning towards a RDBMS, but as I said I've avoided learning MongoDB, so maybe it can achieve what I want. MongoEngine is a Document-Object Mapper (think ORM, but for document databases) for working with MongoDB from Python. The question mark makes the preceding token in the regular expression optional. Just note that until this bug is fixed and released, if you’re using Percona Server for MongoDB and the --fork option while starting the mongod instance you’ll have to provide an absolute path for audit log file instead of relative path. When you are importing data into a MongoDB database, a lot of work and frayed tempers can be saved by preparing data properly before you attempt to create a MongoDB collection. BSON [bee · sahn], short for Bin­ary JSON, is a bin­ary-en­coded seri­al­iz­a­tion of JSON-like doc­u­ments. /' 斜杠。 但是在nodejs中,必须要使用RegExp,来构建正则表达式对象。 其实很简单,一层窗户纸。知道了实现原理,一切都变得很容易。 转载请注明出处:. Thank you for bringing this to our attention. js使用MongoDB lumen 使用 mongodb opentsdb查询cpu使用率 hue. At present, MongoDB supports around 15 languages. MongoDB\BSON\Regex in the PHP. This is the second post in a multi-part series on Indexing in MongoDB, however much of what I talk about can be applied to any database. Press question mark to learn the rest of the keyboard shortcuts. Let’s build a query using Studio 3T’s MongoDB query builder and the Customers replica data set, which can be downloaded here. We're the creators of MongoDB, the most popular database for modern apps, and MongoDB Atlas, the global cloud database on AWS, Azure, and GCP. To quote from the project description, "Instead of writing queries as inline strings or externalizing them into XML files they are constructed via a fluent API. Visit Stack Exchange. This table displays some examples of the syntax and structure of the queries you can use to request data from MongoDB. split() methods in this tutorial with examples. Regex is a series of characters forming a pattern to match. Learn how to detect and prevent NoSQLi (including MongoDB code injections) in your own applications and review some common examples. Use code METACPAN10 at checkout to apply your discount. You can also use regular expression to find exactly what you want to search. Using variable regex with MongoDB query in Node. A Vulnerable NodeJS App with Mongo. It is a document database which imposes very little and has drivers for many programming languages. This is a great way to kick-start your learning on schema design with the document data model. It provides patterns or a sequence of characters for matching text and define search pattern. Trouble figuring out how to anchor a regex in a match (self. To run tests with wire protocol compression, set MONGO_GO_DRIVER_COMPRESSOR to snappy, zlib, or zstd. class bson. Python RegEx or Regular Expression is the sequence of characters that forms the search pattern. Further optimization can occur if the regular expression is a “prefix expression”, which means that all potential matches start with the same string. MongoDB uses Perl compatible regular. This pattern is all about keeping the version history of documents available and usable. Tools for representing MongoDB regular expressions. However, that complete syntax is not widely supported, therefore it is recommended that you stick to the subset of that syntax described below. We can then use this pattern in a string-searching algorithm to "find" or "find and replace" on strings. com is for Java and J2EE developers, all examples are simple and easy to understand, and well tested in our development environment. The question mark is called a quantifier. MongoDB works on concept of collection and document. Last document has an extra field called age. Spring Boot 1. Howto new a query with regex in php? #186. Queries can return specific fields of documents and also include user-defined JavaScript functions. Following is the syntax to use $regex in MongoDB −db. Tools for representing MongoDB regular expressions. A Regular Expression, also known as regex or regexp is a sequence of characters that define a particular search pattern in the formal language theory of theoretical computer science. Observe the documents - it has some names which are in alphabetical order. This course provides you with a practical approach to MongoDB. CSharp Driver LINQ Tutorial This is translated to the following MongoDB query (using regular expressions): {S: /abc$/} enum comparisons (==, !=, <, <=, >, >=) enum fields or properties can be compared to constants of the same enum type. Corey Schafer 424,638 views. If a match is not found, returns null. MongoDB conveniently provides us with an official container. This post is part of a series called An Introduction to Mongoose for MongoDB and Node. This class can be used to create regular expressions. About Author maz. python,mongodb,pymongo. This group is an open forum for discussion of MongoDB Stitch technical questions as well as release announcements. This table displays some examples of the syntax and structure of the queries you can use to request data from MongoDB. This is a great way to kick-start your learning on schema design with the document data model. MongoDb negative look-ahead regex search test. Sharding is the process of storing the data in different machines and MongoDB's ability to process the data, as and when the size of the data grows. Matched IP addresses can be extracted from a file using grep command. There are a number of regex engines that are written in slightly different syntax, but the fundamentals are all basically the same, and in this case, MongoDB uses the Perl Regex (PCRE) engine. Fields can vary from document to document. Regex IsMatch does not seem to work on list-properties although the same LINQ query runs fine on a standard list. This video covers the basic of querying a MongoDB collection including Query Documents, Regular Expression (RegEx) support and the logical operators like "$o. This tutorial covers the support for LINQ queries added in the 1. Escape converts a string so that the regular expression engine will interpret any metacharacters that it may contain as character literals. Regular Expressions (Regex) Tutorial: How to Match Any Pattern of Text - Duration: 37:55. In this post you will see how to query MongoDB by date (or ISODate) using SSIS MongoDB Source. 6, the same is empowered as default in MongoDB. Contribute to mongodb/mongo-python-driver development by creating an account on GitHub. The regular expression syntax used is from JavaScript (ECMA 262, specifically). You can work directly with the product group on this by sending this issue to AskCosmosMongoAPI. The method str. How to Create a MongoDB Case-Insensitive Index. As with LIKE, pattern characters match string characters exactly unless they are special characters in the regular expression language — but regular expressions use different special characters than LIKE does. To quote from the project description, "Instead of writing queries as inline strings or externalizing them into XML files they are constructed via a fluent API. Easily organize, use, and enrich data — in real time, anywhere. So i know that MongoDb checks all of those boxes but the last. Your tutorial was very useful to start with spring-data. 1#712002-sha1:609a505); About Jira; Report a problem; Powered by a free Atlassian Jira open source license for MongoDB. More unusually, they can be saved to the database and retrieved. A Regular Expression or RegEx represents a group of characters that forms a search pattern used for matching/searching within strings. idx: a zero-based index indicating where the first char of the match appears in the text field being searched. A regular expression can be formed by using the mix of meta-characters, special sequences, and sets. RegEx in Python. 在关系型数据库中,通过连接运算符可以实现多个表联合查询。而非关系型数据库的特点是表之间属于弱关联,Mongodb作为Nosql代 表,其本身特性不建议对多Collection关联处理,不过对于有些需要对多表关联处理的需求,Mongodb也可以实现。. Entering a search term in the search field, one can decide to run it with or. If it is not, start MongoDB. You can make several tokens optional by grouping them together using parentheses, and placing the question mark after the closing parenthesis. MongoDB\BSON\Regex in the PHP driver), which may be used as you would an equality query. BSON regular expression data. count(): The db. The question mark makes the preceding token in the regular expression optional. Tutorial #17: Sharding in MongoDB Sharding in MongoDB is explained in detail in this tutorial. Regex splits the string based on a pattern. CSharp Driver LINQ Tutorial This is translated to the following MongoDB query (using regular expressions): {S: /abc$/} enum comparisons (==, !=, <, <=, >, >=) enum fields or properties can be compared to constants of the same enum type. The MongoDB C Driver, also known as “libmongoc”, is a library for using MongoDB from C applications, and for writing MongoDB drivers in higher-level languages. JSON properties are automatically mapped to their equivalent object attributes (and complex ones mapped as sub-attributes). When we create a text index on a field, MongoDB tokenizes and stems the indexed field's text content, and sets up the indexes accordingly. public class Car { public string Name; public List Colors; } this only works for plain list LINQ: var regex = new Regex("^Blue. Python RegEx or Regular Expression is the sequence of characters that forms the search pattern. MongoDB\BSON\Regex::getPattern — Returns the Regex's pattern MongoDB\BSON\Regex::jsonSerialize — Returns a representation that can be converted to JSON MongoDB\BSON\Regex::serialize — Serialize a Regex. StickerYou. Learn how to use Robo 3T with Azure Cosmos DB's API for MongoDB. However, that complete syntax is not widely supported, therefore it is recommended that you stick to the subset of that syntax described below. What is MongoDB? MongoDB is a document-oriented NoSQL database used for high volume data storage. Using regex Expression in an Array. Python provides support for regular expressions via re module. About Author maz. If you would like to know more about regular expressions and how to use them in JavaScript, check out my Regex course. yourCollection. Extract a substring by matching a regular expression. MongoDB Regular Expression. Just note that until this bug is fixed and released, if you’re using Percona Server for MongoDB and the --fork option while starting the mongod instance you’ll have to provide an absolute path for audit log file instead of relative path. This table displays some examples of the syntax and structure of the queries you can use to request data from MongoDB. MongoDB Atlas is a fully-managed cloud database developed by the same people that build MongoDB. Creating an Magento BI MongoDB user. In this free course you will learn how Mongodb can be accessed and its important features like indexing, regular expression, sharding data, etc. The official MongoDB container. Please note that once you do these steps, it's harder to downgrade back to 3. Training Summary MongoDB is a document-oriented NoSQL database used for high volume data storage. Here we switch to using the regular MongoDB shell and commands to make the study of aggregate functions simpler. In our previous post we discussed how to query/load MongoDB data (Insert, Update, Delete, Upsert). Drag and drop fields. MongoDB offers a variety of cloud products, including MongoDB Stitch, MongoDB Atlas, MongoDB Cloud Manager, and MongoDB Ops Manager. Here are some examples of how to split a string using Regex in C#. The regular expression syntax understood by this package when parsing with the Perl flag is as follows. To see full detail about possible query syntax see online help. ORIGINAL ANSWER: It should be noted that searching with regex's case insensitive /i means that mongodb cannot search by index, so queries against large datasets can take a long time. Several scalar data types are of specific interest to MongoDB and the format is used both as a data storage and network transfer format for the MongoDB database, but it can be used independently outside of MongoDB. Typically, these expressions will be used to query the database and find matching strings. As for the performance. Serialization. In this post you will see how to query MongoDB by date (or ISODate) using SSIS MongoDB Source. I’ve already covered Change Streams and Retryable Writes in previous posts. It's extremely popular and MongoDB developers are in high demand. Since this token is a zero-length token, the engine does not try to match it with the character, but rather with the position before the character that the regex engine has reached so far. Now that SQL Server can understand and shred JSON data, SQL Server and MongoDB can easily cohabit and pass data between them. Instead of the expected interleaving That would be the expected behavior only for synchronous I/O. x release notes. What is the Python Regular Expression (Regex)? Essentially, a Python regular expression is a sequence of characters, that defines a search pattern. MongoDB document databases provide high availability and easy scalability. springdata整合mongodb一些方法包括or,and,regex等等 - springdata 整合 mongodb 一些方法包括 or,and,regex 等等 这几天接触 mon. MongoDB has a rich query system that allows you to select and filter documents using the aggregation pipeline framework. In this article, we will show you how to create a Spring Boot + Spring Data MongoDB application, using Gradle build tool. 2 upgrades embedded MongoDB Shell to 4. count(): The db. Arnold Schwarzenegger This Speech Broke The Internet AND Most Inspiring Speech- It Changed My Life. While convenient to use, I had some questions about how MongoDB regex performance stacks up to regex performance in other (SQL) Databases. Tools for representing MongoDB regular expressions. When you query a database, you’re not always looking for an exact string match. Fiddling with regex select to multi valued attributes in MongoDB. In this article, we are going to discuss how to Use Regular Expressions in Mongodb. This module provides a BSON type wrapper for a PCRE regular expression and optional flags. Regular Expressions are habitually utilized within all dialects to search down an example or word in any string. Extending this topic here by Ivan Breet a bit more. In this article, I'll be demonstrating how some real data can be imported into MongoDB and then cleaned up using aggregation and regex to better gain insights. org - there is currently a tutorial, a user guide and API reference. However, that complete syntax is not widely supported, therefore it is recommended that you stick to the subset of that syntax described below. However these MongoDB regex queries have a downside, all but one type of regex makes poor use of indexes and results in performance problems. How to Speed-Up MongoDB Regex Queries by a Factor of up-to 10. Mongodb now supports advanced full text searching, with many features. This post will cover a feature which expands upon the document validation feature from MongoDB 3. Tutorial #17: Sharding in MongoDB Sharding in MongoDB is explained in detail in this tutorial. Online regex tester, debugger with highlighting for PHP, PCRE, Python, Golang and JavaScript. You can use a regular expression in the to look for strings that match a certain pattern. Mongodb now supports advanced full text searching, with many features. Regular expressions are a powerful and standardized way of searching, replacing, and parsing text with complex patterns of characters. In this post, we’ll show you how to use MongoDB connection pooling on AWS Lambda using both Node. The "insert" command can also be used to insert multiple documents into a collection at one time. We will provide code snippets explaining how to use both features in a Java application as well as an empirical performance evaluation. Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. regex : does not begin by “pattern” Thanks. In our previous post we discussed how to query/load MongoDB data (Insert, Update, Delete, Upsert). MongoDB stores data using a flexible document data model that is similar to JSON. There are a number of regex engines that are written in slightly different syntax, but the fundamentals are all basically the same, and in this case, MongoDB uses the Perl Regex (PCRE) engine. This article explains you how to write a mongo query to perform a LIKE match in MongoDB. So i know that MongoDb checks all of those boxes but the last. class bson. A set of related data in MongoDB is referred to as a “collection”. The rows dont differ in columns, so there really dont is a need to store the attribute names for each entry, my data is not unstructred. Training Summary MongoDB is a document-oriented NoSQL database used for high volume data storage. If pacman alerts you that a new configuration file is saved at /etc/mongodb. How to update a single field in a MongoDB collection for all documents matching a specific criteria - MongoDB update all matching. string returns the string passed into the function. Options in aggregation queries are not supported. Mongo shell is an interactive JavaScript interface to MongoDB used to perform administrative operations and also query and update data. ORIGINAL ANSWER: It should be noted that searching with regex's case insensitive /i means that mongodb cannot search by index, so queries against large datasets can take a long time. This database have a collection: Product collection. MongoDB is a document-oriented NoSQL database used for high volume data storage. The behaviour of log rotation in MongoDB differs according to the value of the parameter logRotate which was introduced in version 3. 3 Norberto Leite Developer Advocate Twitter: @nleite [email protected] 查询使用 regex的使用 in查询使用 laravel使用mongodb MongoDB的使用 MongoDB使用mapReduce MongoDB MapReduce 使用 mongodb使用 mongodb引用查询 备查使用 MONGODB使用 使用 使用 使用 使用 使用 使用 使用 常用查询 CodeSmith 使用与NetTiers 使用 C# MongoDB C&C++ lumen mongodb使用 node. Static import of the 'Criteria. To start MongoDB, run the following command in a terminal. We can use single or multiple \s without a problem. Please note that once you do these steps, it's harder to downgrade back to 3. The trick is to utilize regular expressions (or regex for short), which is basically a text string that defines a search pattern. The regular expression syntax used is from JavaScript (ECMA 262, specifically). Covers the latest version 3. mongoDB - find by regex. MongoDB\BSON\Regex in the PHP driver), which may be used as you would an equality query. Add MongoDB Array using insert() with Example. It’s used mainly to search for all matches with all groups. Learn the MongoDB from scratch. Remember that these operations are all asynchronous, which is a key idea of node. Documents contain one or more fields, including arrays, binary data and sub-documents. The first argument of the find() method is a query object, and is used to limit the search. For case sensitive regular expression queries, if an index exists for the field, then MongoDB matches the regular expression against the values in the index, which can be faster than a collection scan. The image below shows the sample data that we're using for the Regex queries throughout this articles:. search(), re. Learn re module, re. Press J to jump to the feed. In our previous post we discussed how to query/load MongoDB data (Insert, Update, Delete, Upsert). Fields in a MongoDB document can be indexed with primary and secondary indices. This mongodb find document tutorial covers a number of ways to query a single document or find multiple documents based on same condition as we do in SQL using WHERE CLAUSE. We're the creators of MongoDB, the most popular database for modern apps, and MongoDB Atlas, the global cloud database on AWS, Azure, and GCP. Manage your data with a system designed to support modern application development. The [56] atom matches 5 or 6, allowing the pattern to match on 7. The regular expression syntax used is from JavaScript (ECMA 262, specifically). Using MongoDB. The Aggregation Framework Examples page in the MongoDB wiki provides additional examples of function calls. Here's a typical regex query. When you have imported the re module, you can start using. MongoDB is Fully Featured 7. Last document has an extra field called age. MongoDB, like some other NoSQL databases (but not all!), stores its data in documents using a JSON structure. Characters in the flags argument will be sorted alphabetically when a Regex is constructed. com is for Java and J2EE developers, all examples are simple and easy to understand, and well tested in our development environment. To start MongoDB, run the following command in a terminal. This group is an open forum for discussion of MongoDB Stitch technical questions as well as release announcements. The trick is to utilize regular expressions (or regex for short), which is basically a text string that defines a search pattern. We will follow with the basic CRUD operations as they are the best to start with. Our standalone MongoServer used PCRE(Perl compatible regular expressions) but Cosmos using ECMAScript regex expressions. You get a fast overview of your data's behaviour and you can easily identify a bottleneck or a slow query that could be causing performance issues, which means you can get an even faster solution for your problem. Introduction¶. Alternatives to Full-Text Search in MongoDB. where' method will improve readability. Table of Contents 1) Select all documents from a collection 2) Select first document from a collection 3) Select single document and limited field(s) from a collection 4) Select all. We could construct a system that uses a dedicated version control system in conjunction with MongoDB. Regular Expressions This tutorial will explain Regular Expression in MongoDB in a detailed manner. What is AWS Lambda? AWS Lambda is an event-driven, serverless computing service provided by Amazon Web Services. Since this token is a zero-length token, the engine does not try to match it with the character, but rather with the position before the character that the regex engine has reached so far. The rows dont differ in columns, so there really dont is a need to store the attribute names for each entry, my data is not unstructred. Flags will be sorted and duplicates will be removed during object. js driver for the database in your app. We'll illustrate this by going through some examples of different MongoDB regex queries and how they can cause issues for your database. Open ended regex operations cannot use an index. This makes it easy to create and modify rules that ensure that all documents written to a collection contain the data you expect to be there. : String Operation « Regular Expressions « Java. Learning MongoDB will show you how to install, configure, and secure MongoDB to meet the demands of modern enterprise data systems. Consider below document structure under posts collection containing post text and its tags. Today we would like to introduce you to the new MongoDB Full Text Search and compare its capabilities and performance with simple regular expressions, which are currently state of the art for searching in MongoDB. Spring Boot 1. The behaviour of log rotation in MongoDB differs according to the value of the parameter logRotate which was introduced in version 3. Along with this, we will learn how to use regex in array element in MongoDB and query optimization.