NAV: SLTechnology News&Howtos > Database >

• 

  Accumulation of common sentences in SQL

  Accumulation of common sentences in SQL: 1. SQL basic sentences SQL Classification: DDL-data definition language (Create, Alter, Drop, DECLARE) DML-data manipulation language (Select, Dele)

  2022-06-01 16:56:37 Views: 251
• 

  Installation and configuration of graylog2 (v2.0.3)

  I made a lot of effort, but looking back, it's not difficult. I'd better write it down and write it down. When I installed myself, I read an old version of the installation manual, took a lot of detours, and finally referred to the official manual, which was easily and quickly installed. Official website address: http://gr

  2022-06-01 16:56:29 Views: 299
• 

  Set other fields to self-increment primary key

  1. Create a test table and view the table structure mysql > desc test_autoinc;+-+-

  2022-06-01 16:56:28 Views: 220
• 

  SQL Plan execution interval problem (MSSQL)

  If you set the execution interval of a scheduled task to 10 seconds, the planned execution is as follows: 1: the stored procedure is executed in 1 second, then run again after 9 seconds, 2: the stored procedure runs in just 10 seconds, and starts the next time immediately. 3: the running time is more than 10 seconds, and the whole stored procedure is completed normally.

  2022-06-01 16:56:28 Views: 287
• 

  Oracle Chinese sort NLSSORT

  Today found a very interesting function: NLSSORT, found that Chinese can be sorted by pinyin, strokes, radicals, so check the relevant information, the results are as follows: Oracle 9i, added according to pinyin, radical, stroke sorting function. This is achieved by setting the NSL_ sort value.

  2022-06-01 16:56:28 Views: 237
• 

  9 common Redis interviews

  9 common Redis interview "difficult" questions 1 what is the data structure of Redis? String String, dictionary Hash, list List, collection Set, ordered collection SortedSet. If you are a medium and advanced user of Redis, you need to add the following

  2022-06-01 16:56:28 Views: 210
• 

  CentOS compiles and installs php extensions for MongoDB and mongoDB

  System: centOS5.6 downloads mongo source code package, pcre,epel,js1 # wget http://downloads.mongodb.org/src/mongodb-src-r1.8.1.tar.g

  2022-06-01 16:56:27 Views: 246
• 

  Linux configuration oracle sqldeveloper

  After installing sqldeveloper and jdk, you can switch java versions to either update-alternatives-- config javaalternatives-- config java configuration / etc/p.

  2022-06-01 16:56:27 Views: 245
• 

  Detailed description of mysqldump parameter

  Mysqldump parameters Daquan 1, mysqldump backup: mysqldump-u username-p password-h host database-w "sql condition"-lock-all-tables > path 2, mysqldum

  2022-06-01 16:56:27 Views: 271
• 

  Ubuntu install mongodb

  Sudo apt-key adv-- keyserver keyserver.ubuntu.com-- recv 7F0CEB10 creates a / etc/apt/sources.list.d/10gen.

  2022-06-01 16:56:27 Views: 299
• 

  Postgresql-- string function

  String function: the string functions in postgresql are: calculating string length function, string merging function, string replacement function, string comparison function, finding specified string position function, and so on. 1. A function that calculates the number of characters and the length of a string: char_len

  2022-06-01 16:56:26 Views: 245
• 

  Spring Data JPA instance query

  3. Understanding "instance query" 1. Concept definition: in the above example, the "instance" is created as follows: Example ex = Example.of (customer, matcher); we can see that the Example object is created by custome

  2022-06-01 16:56:20 Views: 229
• 

  Distinguish between master and slave tables in a relational row database

  1. Foreign keys are often used in the design of the database, and beginners are often confused, which is summed up according to my experience. Primary table: the table in which the primary key (primary key) is located is called the primary table, and the primary key in the primary table is used to associate with other tables. The primary key is unique and cannot be nu.

  2022-06-01 16:56:17 Views: 286
• 

  Lnmp installation-source code installation mysql5.6-nginx-php-memached

  LNMP-"Source packing nginx mysql5.6 php1. Unlock the mysql5.6 source package # tar-zxf mysql-5.6.25.tar.gz#cd mysql-5.6.25 before installing mysql#

  2022-06-01 16:56:17 Views: 296
• 

  PLS-00201: ORA-20000:

  PLS-00201: identifier 'SYS.DBMS_SHARED_POOL' must be declared1 what is DBMS_SHARED_POOLMos interprets The DBM

  2022-06-01 16:56:16 Views: 208
• 

  Installation MySQL error-bash: mysql: command not found

  After installing MySQL (installation files), you cannot mysql directly on the command line. Because the command line looks directly for the commands under / usr/local/bin, we need to put the commands of mysql into .bash _ profile. Vim / .ba

  2022-06-01 16:56:16 Views: 201
• 

  Mongo replica set mongos startup error

  The background project stores data in the form of mongo replica set, which often leads to the problem that a copy mongos cannot be started due to an unexplained power outage. Environment introduction mongodb copy set: mongo01:192.168.36.218mongo02:192.

  2022-06-01 16:56:16 Views: 245
• 

  Optimization based on cost-- CBO

  Choose the optimization mode of CBO. By default, CBO takes the throughput of SQL statements as the optimization goal. There are three different optimization methods.

  2022-06-01 16:56:07 Views: 208
• 

  & # 8203 the difference between NOSQL and relational database

  There are bottlenecks in relational databases. 1. the concurrency of users of websites with high concurrent read and write requirements is very high, often reaching tens of thousands of read and write requests per second. For traditional relational databases, hard disk Iscrap O is a big bottleneck. 2. The efficient reading and writing of massive data produces a huge amount of data every day.

  2022-06-01 16:56:04 Views: 202
• 

  Why should we suggest using self-increment column as primary key?

  The first part is the characteristics of InnoDB engine table 1. InnoDB engine table is an index organization table based on B + tree (IOT) about the characteristics of B + tree B + tree: (1) all keywords appear in the linked list of leaf nodes (dense index), and the keywords in the linked list happen to be ordered.

  2022-06-01 16:55:55 Views: 276