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  How to write better SQL queries: the Ultimate Guide-part 3

  This time we'll learn the last article in the series "how to write better SQL queries." Time complexity and the big O symbol through the first two articles, we already have some understanding of the query plan. Next, we can further explore and think about the improvement of performance with the help of the theory of computational complexity.

  2022-06-01 16:33:30 Views: 286
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  Linux silently installs Oracle11g R2

  A configuration base environment first makes a comprehensive update of the operating system # yum update installs and upgrades the oracle dependency package # yum-y install\ binutils\ compat-libcap1\ compat-

  2022-06-01 16:33:30 Views: 241
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  Php_mongo.dll download (required for php operation mongoDB)

  Php_mongo.dll download (required for php operation mongoDB) if PHP connection operation mongoDB, you must add this extension: php_mongo.dll, put it in your corresponding php extension directory and add: ex to your php.ini

  2022-06-01 16:33:29 Views: 246
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  Critical point in nonclustered index (Tipping Point)

  What is the tipping point? Note that the problem I want to say is that the execution plan of nonclustered indexes has changed from Seek+Lookup to the tipping point of Table/Clustered Index Scan. The smallest IO unit for SQL Server to access data is a page. We know

  2022-06-01 16:33:24 Views: 284
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  The skills of using redis Database

  Today, I will talk to you about the skills of using redis database. I believe most people don't know these skills yet, so I give you a summary of the following. I hope you can get something after reading it. 1. Stop using KEYS * Okay and start this article by challenging this command

  2022-06-01 16:33:23 Views: 230
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  Analysis of the problem that the downtime of one node of Oracle RAC leads to the HANG of another node

  As the saying goes, "it never rains but it pours." there is a set of 2-node Oracle 11.2.0.4 database in production, of which 2 nodes are down due to hardware failure and 1 node goes to HANG to live. Let's analyze this fault together. At 04:30 in the morning, he was on duty and telephoned to say that a set of production warehouse node 2 was down.

  2022-06-01 16:32:59 Views: 286
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  Database of python

  Homework content 1, query the names of all courses and the names of the corresponding teachers 2, query the number of boys and girls in the student table 3, query the names of students whose physics scores are equal to 100, query the names and average scores of students with an average score of more than 80, and query the names of all students.

  2022-06-01 16:32:59 Views: 291
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  Mysql Partition and Sub-Table (1)

  Mysql partition sub-table 1. Sub-table is to decompose a large table into several physical tables with independent storage space according to certain rules, each table corresponds to three files, MYD data file, .MYI index file, .frm table structure file mysql sub-table is divided into vertical segmentation and horizontal segmentation.

  2022-06-01 16:32:36 Views: 262
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  How to realize master-slave fault switching in Redis sentinel mode

  How does Redis Sentinel mode switch between master and slave failures? I believe that many novice rookies have not yet learned this skill. Through the summary of this article, I hope you can learn this skill. The following materials are the steps for implementation. Redis Sentinel is a distributed system, you can

  2022-06-01 16:32:26 Views: 221
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  Huayun Internet & Jie Technology will jointly create the high-end secondary data market in China.

  As the world's leading provider of software-defined storage and super-converged system solutions, D-UNI Jie Technology, the world's leading provider of software-defined data environment and database pooling system solutions, will be based on the understanding of the core data needs of Chinese enterprise users.

  2022-06-01 16:32:11 Views: 223
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  4. Data types and operators of MySQL

  Introduction to MySQL data types MySQL supports a variety of data types, including numeric type, date / time type and string type. Numeric data types: including integer types TINYINT, SMALLINT, MEDIUMINT, INT, BIFI

  2022-06-01 16:32:11 Views: 276
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  Java encapsulates the Mongodb3.2.1 utility class

  Since the recent project has to use mongodb to deal with some logs, I learned some basic usage of mongodb in advance and probably wrote some commonly used ones. The development environment is: WIN7-64jk 7-64maven 3.3.9-64meme IDEA2017

  2022-06-01 16:32:07 Views: 278
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  Brief explanation of RMAN command

  RMAN Command Abbreact 1 list scene number RMAN > list incarnation;2 list backup 2.1.Overview of available backups RMAN > list backup summary; B means backup F means FULL

  2022-06-01 16:32:07 Views: 224
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  Actual combat: the use of ORACLE SQL Performance Analyzer

  With SPA, you can play specific SQL or entire SQL loads based on various types of changes, such as initialization parameter changes, optimizer statistical refreshes, and database upgrades, and then generate comparison reports to help you assess their impact. In Oracle Database

  2022-06-01 16:32:07 Views: 206
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  Detailed resolution process of error reporting when installing JDK in tomcat

  The following error occurred while unzipping the installation of JDK while installing tomcat: [root@localhost src] # wget 'http://download.oracle.com/otn-pub/java/jdk/8u6

  2022-06-01 16:32:06 Views: 275
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  Detailed introduction of Redis cache database configuration file

  Today, the editor to share with you is a detailed introduction of the Redis cache database configuration file, I believe that most people do not understand, in order to make you better understand, the editor summed up the following content, do not say much, let's look down. 1. At the beginning, it shows that there is nothing to say here, but it is important to pay attention to the latter.

  2022-06-01 16:31:43 Views: 201
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  MongoBD Learning (3) insert and query data

  Root@adela-vm:/opt/mongodb_simple# numactl-- interleave=all bin/mongod-f conf/mongod.confabout to f

  2022-06-01 16:31:42 Views: 287
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  Analyze the regular burr phenomenon of ADG network card traffic

  First, introduce the customer's ADG environment. The newly launched business system is monitored by ZABBIX. It is found that the ADG Nic traffic exceeds 1m every half hour. After 2 minutes, the average network traffic is about 100K. 2. Analysis 1. The backup database traffic in ADG environment mainly comes from the main database r

  2022-06-01 16:31:42 Views: 207
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  [MySQL] [copy] use slave_exec_mode to deal with 1062 and 1032 errors during replication

  [MySQL] [copy] use slave_exec_mode parameters to deal with 1062 and 1032 errors during replication background: ​ brother Zhang used pt-slave-restart to skip after asking about the 1032 error between master and slave in the group today.

  2022-06-01 16:31:42 Views: 228
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  Detailed explanation of Oracle cold backup [actual combat case]

  Detailed explanation of Oracle cold backup-- preparation work select * from vested database

  2022-06-01 16:31:42 Views: 202