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preface As we all know, at the end of last year, jsdelivr, a well-known free CDN service provider, had no domestic CDN acceleration due to the problem of domain name filing in the mainland. At present, it can only be parsed overseas, which is not only slow, but also occasionally unable to connect to the server. Therefore, many domestic website ...

1. Database and SQL 1-1 introduction to database Our common mysql, SQL Server, DB2, Oracle Database and Postgresql all belong to relational database management system (RDBMS) The tables stored in the database are all sheets, which can be compared to excel data sheets. They are basically the same, just like that. 1-2 introduction to SQL The ...

query Simple query Query all mysql: SELECT e.* From emp e oracle: SELECT e.* From emp e; Query specific columns mysql: SELECT e.empno,e.ename,e.job from emp e oracle: SELECT e.empno,e.ename,e.job from emp e Alias use mysql: select e.empno 'Employee number',e.ename 'Employee name',e.job 'Employee position',e.mgr 'Superior ...

i18n internationalization In development, Internationalization, also known as localization, means that a website (or application) can support multiple different languages, that is, different words can be displayed according to the language type and country / region of the user. It can make it easy for users in different countries and languages ...

Introduction and description Four traditional mainstream databases:     Oracle MySQL SqlServer DB2 Non relational database: Redis MongoDB The mainstream database is relational database: there is an association relationship between tables When we say install database, we mean install database service When creating a database, it refers t ...

/******************* postgresql database test starts***********************/   --This test is based on pg database version 10.11 postgres=# select version();                            version -------------------------------------------------------------  PostgreSQL 10.11, compiled by Visual C++ build 1800, 64-bit (1 Row record) --Create a ...

This case comes from a production failure of a two node rac of a customer. The phenomenon is that a large area of gc buffer busy acquire leads to business paralysis.First, check the AWR header information and load profile of node 1:1 node AWRKey information points obtained:For LCPU 256 system, AAS=13379.42/59.91=223, indicating that the system ...

1, Windows system Oracle provides the function of starting with the startup of the operating system. There are different setting methods in Windows and Linux. In windows, you can modify "my computer – > management – > services – > oracleservice $oracle_sid", or directly use Win+R to open the running wi ...

This case comes from an SQL optimization of a customer in Xi'an. The optimization itself is not complex, but an interesting problem is found, that is, the index range scanning and back table all use multi block reading. Let's take a look at specific cases.SQL text:UPDATE A_INV_PRINT_DET P SET (P.P_POWER, P.N_POWER, P.V_POWER, P.P_KWH_PRC, P.N_K ...