mongodb query performance

Common query indexes of mongoDB (III)1. _ id index is the default index created by the vast majority of sets. For each inserted data, MongoDB automatically generates a unique _ id field. > Db. jerome_2.collection.insert ({x: 2}) WriteResult ({"nInserted": 1})> db. jerome_2.collection.getIndexes () [{"v": 1, "key": {"_ id": 1}, "name": "_ id _", "ns ": "jerome. je

mongotest.php, set the user name and password required for the connection, and establish a database connection $conn = new Mongo ("Mongodb://localhost:27017//admin:admin");The default user and password is adminSelect Database Blog, if not, create$db = $conn->blog;can also be written: $db = $conn->selectdb (' blog ');Develop result set (table name: Posts)$collection = $db->posts;Can also be written as: $collection = $db->selectcollection (' pos

Start MongoDB: sudo service mongodb start ,mongo After testing, the key can be quoted or not added, but the value is generally quoted, except for the value type MongoDB is case-sensitive, and naming is usually based on the camel-named method MongoDB will be created automatically if the database/collect

Tags: base min value val opened result mongod import ISP Simple query: Use a custom Xxxrepository interface. (See Chapter 11th Springboot + mongodb (simple query)) Complex Queries : Building classes with mongotemplate and some query criteria (basicdblist, basicdbobject, criteria, etc.) 1, Application

MongoDb stores two collections, which have the same structure. Currently, you need to perform paging queries. MongoDb does not support Join-like functions and cannot perform data merging and sorting. Considering using PHP for this feature, we are worried about performance and speed. Ask if there are other... two collections are stored in

larger, or nscanned is much larger than nreturned, it means that the database scans many objects to find the target object, so you need to index the query criteria. When the returned result set is large, i.e. the ResponseLength value is large, the performance is degraded, and a second query parameter is added to the Find

. Database username Password The database username and password are empty by default after successful startupPHP Mongod Extended installation Download: http://download.csdn.net/detail/dupingjin/7577217 Select the appropriate extension based on the PHP version, which is used here Php_mongo-1.4.5-5.5-vc11-nts.dllInto PHPDirectory extfolder under Modify PHP.ini To increase at the end of a line or php.ini extension. Extension=php_mongo-1.4.5-5.5-vc11-nts.dllRestart the Php/nginx/apache environme

Recently wanted to do a front-end control Interface field return of a basic method, through the MongoDB find ($query, $field) query to specify the fields of the query, but encountered such a problem:There are two encapsulation methods in the work code:/*** Query a record* @p

Tags: mongodbIn the last blog, there is three query condition to be described. In the blog, we'll continue to what we had leant in the last blog.1 $mod' $mod ' operation is able-make us-to-do simple mod operation, and is no need to use where sentence.\2. $ne, $in, $nin' $ne ' means not equal.' $in ' is same as key word ' in ' in relationship. $nin is opsitive to ' in '3. $or and $norDurning the mutiple conditions, then result would be is return that i

First use the official C # access component https://github.com/mongodb/mongo-csharp-driverThen, reference MongoDB after compilation. bson. dll and MongoDB. driver. dll, and declare reference to using MongoDB In the cs file. bson; using MongoDB. driver; using