mongodb query performance

, there are two ways to set the method and level, one is to add the –slowms boot parameter configuration. The second is to add the second parameter when calling Db.setprofilinglevel: Db.setprofilinglevel (level, slowms) db.setprofilinglevel (1, 10); 2. Query Profiling Records Unlike MySQL's slow query log, MongoDB profile records are directly present in the sys

MariaDB [(None)]> show processlist;+--------+--------+------------------+---------+-------------+---------+---------------+----------------------+ --------| Id | User | Host | db | Command | Time | State | Info | Progre| 287662 | Root | localhost:41583 | Finance | Query | 665767 | Sending Data | SELECT COUNT (*) from ' cash_beorder ' INNER JOIN ' Cash_account ' on (' Cash_beorder '. ' account_id ' = ' CA | 0.00| 287663 | Root | localhost:41626 | Fina

Mysql database performance optimization sub-query and mysql database performance optimization I remember that when I was working on a project, I heard a sentence and tried not to use subqueries. So let's take a look at this article to see if this sentence is correct. Before that, we need to introduce some conceptual things and mysql's rough statement processing.

MongoDB (3)-add, delete, modify, and query operations MongoDB, as a non-relational database, is very different from the addition, deletion, modification, and query of traditional databases. Here we only outline the knowledge points. In actual use, we can use Baidu for details. Let's take a look at several major aspects

Tags: mongodb slow query Analysis script1 IntroductionThis is used in the production environment of a MongoDB slow query log automatic collection of scripts, the original idea to write this script is to facilitate the collection of slow query logs and facilitate analysis. Be

Use Yii2-mongodb in the YII2 inside the main to improve which piece of performance? Reply content: Use Yii2-mongodb in the YII2 inside the main to improve which piece of performance? MongoDB is a NoSQLMySQL is the traditional dbAs for the

required by the query result is fully iterated. For the example above, the limit (1) indicates that the output is only one, and if it is less than 1, it is not output, that is, the limit (n) function qualifies the maximum output. Skip (4) means that the first 4 documents in the query result are skipped, and if the result is less than 4, no document is returned. The sort ({"X": 1}) is used to set the

MongoDB version 3.2 Wiredtiger storage engine performance test Chszs, not allowed to reprint without Bo master. Permission to reprint should be marked by the author and blog home: Http://blog.csdn.net/chszsMongoDB 3.2 was recently released, and it uses Wiredtiger as its default storage engine. Over the past five years, MongoDB has evolved from birth to popularity

using PowerShell Call Mtools Analyze MongoDB performance and send mailProblem Description:In MongoDB daily operations, it is often necessary to view the trend graph, slow query, overflow statement, and connection source of the number of connections.Solution:1. Mount the Windows Backup machine directory to the

(doc, current) {" +"Return doc; \ n" +"};";Protected void Page_Load (object sender, EventArgs e){Init (); Var mrb = DB ["posts1"]. MapReduce (); // attach_gfstream.filesList Using (var mr = mrb. Map (mapfunction). Reduce (reducefunction )){Foreach (Document doc in mr. Documents){PostDoc. Add (Document) doc ["value"]);}}This. Mongo. Disconnect ();} The following is the running query result: The map/reduce method has many other methods. If you are int

without any parameters:Db.post.find ()Pretty () statementpretty () can make the results of the query output more aesthetically pleasing. Db.post.find (). Pretty ()And in MongoDBwhen multiple key-value pairs are passed in Find (), MongoDB handles them as an and query. Usage: Db.mycol.find ({key1:value1, key2:value2}). Pretty () Db.post.find ({"By": "Shiyanlou",

C1 = db.testtable.find (). Sort ({"X": 1}). Limit (1). Skip (4); > var C2 = db.testtable.find (). Limit (1). Sort ({"X": 1}). Skip (4); > var C3 = Db.testtable.find (). Skip (4). Limit (1). Sort ({"X": 1}); At this point, the query is not executed, all of these functions are constructs the query, when executes the following statement, the query will be

In the four CRUD operations, a record or document is obtained from the collection of mongodb databases. For non-DBAs, query is the most used. Therefore, if you have learned the query, it will be of great help for us to better operate the database in the future. You can use the following two methods to obtain a data or document from a collection in

Tags: MongoDB performance optimizationMongoDB Linux performance optimization: https://docs.mongodb.com/manual/administration/production-notes/#allocate-sufficient-ram-and-cpuPerformance optimization:1. Close the Atime storage volume that contains the database files.2, according to the recommendations in the Ulimit reference, the file descriptor limit,-n User proc

Tags: div float SQL Time blog host Mail database service hrefPrepare can solve the large-volume Web site to the database server load and cost, this article through an example to introduce the pre-query prepare and the performance of ordinary query comparison, the need for friends can refer to. The instance code is as follows: PHPclassTimer { Public $StartTime= 0;