MongoDB

Go directly to code (dependency code check previous blogs): public void query () {//$or (data with Query ID equal to 1 or ID equal to 2) basicdbobject queryobject = new Basicdbobject (). Append (Queryoper Ators.or, new basicdbobject[] {new

MongoDB Common troubleshooting tools 1.profile Profiling levels: 0, close profile;1, only crawl slow query; 2, crawl all data. start profile and set profile level: Can be launched through the MONGO shell, but also through the Drive Profile

In MySQL, the slow query log is often used as the basis for us to optimize the database, if there is a similar function in MongoDB? The answer is yes, that's MONGO database Profiler. Not only, but also some slow Query than MySQL Log for more

Background Introduction: Querying MongoDB configuration parameters, you can know that the parameter about the maximum number of connections is Maxconns. However, after you connect the instance, look for the maximum number of connections that are

Overview of deleting Recordsin MongoDB, the Db.collection.remove () method is used to delete records in the collection. You can delete all records, delete all eligible records, or delete only one record.Delete all recordsdeletes all the records in

MongoDB data dumpTo create a backup database in MongoDB, you should use the Mongodump command. This command dumps all data from the server to the dump directory. There are many options available through which you can limit the amount of data or

The advantages of MongoDB compared to relational databases:① Weak consistency (eventually consistent), to ensure the user's access speed:For example, in a traditional relational database, a count type of operation locks the dataset so that the exact

Today downloaded the "MongoDB The Definitive Guide" electronic version, browsing the content inside, or quite rich. is a supplement to the actual application of official website documents. Similar to the official documentation, the introduction of

Transferred from: Programming and technologyIf you get the warning when you connect to MONGO shell in Mac OX X:* * Warning:soft rlimits too low. Number of files is a, should be at least 1000A simple-to-be-setting the limit just before starting with

1.MongoDB starts from a configuration fileCreate configuration file:/usr/local/mongodb/etc/mongodb.confThe contents of the configuration file are:#Directory and relavent setdbpath =/var/mongodb/datalogpath =/var/mongodb/logs/log.logprofile=2slowms=10

Database Partitioning Overview When the data in the database table increases, the query speed of the data will inevitably decrease, and the performance of the application will decrease. In this case, we should consider partitioning the table, data

This article mainly tells you the actual operation process of correctly updating the execution plan in the DB2 database. Like the Oracle database, the analytics of your SQL in DB2 also uses the optimizer, generate an Access Plan ). The DB2 optimizer

Today we will mainly talk about the DB2 Performance Tuning design and configuration of your database. There are many database design and configuration options that can affect the query performance. For more suggestions on Database Design, see the

Today, we mainly describe how to minimize the planned downtime of DB2 9.7 database online mode changes when modifying database objects. We all know that IBM®DB2®9.7 introduces new enhancements that allow you to change database objects and ensure

The following article describes how to correctly connect an SQL Server database to a DB2 Server, the following describes the actual operation steps for connecting an SQL Server database to a DB2 Server. I hope this will help you in your future

This article focuses on the introduction of local partition indexes in DB2 V9.7. the DB2 V9.7 database introduces the concept of partition indexes in a range partition table, this mainly adds a new feature selection for the customer based on the

The following articles mainly describe the basis of the DB2 SQL stored procedure. The stored procedure is simply procedure. To learn this, we must first understand another concept: routine, which is generally translated into "routines ". Routine:

This article mainly introduces the data movement function of the IBM DB2 database, this section describes how to use commands of the DB2 database to import and load data from files in a certain format to tables in the database. The so-called data

The selection of DB2 performance optimization policies determines the effect of database optimization. The following describes the considerations for optimizing the performance of ten DB2 databases. I hope this will help you learn about the

DB2 time and date function 1. To use SQL to obtain the current date, time, and time stamp, see the appropriate DB2 register: www.2cto.com SELECT current date FROM sysibm. sysdummy1SELECT current time FROM sysibm. sysdummy1SELECT current timestamp