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In the absence of visualization tools to monitor database performance, common scripts come in handy. Here are a few scripts related to Oracle Performance for your reference. The following scripts have passed the Oracle 10g test, and Oracle 11g may need to be adjusted accordingly. 1. Find SQL statements with the most buffer \ ...

Tools: CMD sqlplus Content: basic table operation, plsql programming (branch structure, loop, judgment, etc.) Account: scott preparation in advance Tips for using cmd Because the author uses sqlplus and enters in the cmd environment. It's not easy to edit the text in cmd environment, so I'll give you some tips. A ...

Author: empty https://segmentfault.com/a/1190000021109130 Problem description A few days ago, I was helping my colleagues to troubleshoot the occasional thread pool errors on the production line. The logic was very simple. The thread pool performed an asynchronous task with results. However, there have been occasional errors recently: java.ut ...

There is no function index function of Oracle in MySQL. It is not accurate to call the Generated Column of MySQL as "function index", but it can achieve the same effect as the function index. Some people also call this feature "derived column". What is Generated Column The value of Generated Column is calculated according to ...

With the increasing business load, containerization and virtualization have become the necessary capabilities for all kinds of online applications. For distributed database, containerization is also a good way to improve rapid deployment and operation and maintenance efficiency.   We have re optimi ...

The string processing function of Oracle 1. Convert string to uppercase Format: UPPER(string) Give an example: SQL> select UPPER('I am a student!') AS RESULT from dual; RESULT --------------- I AM A STUDENT! 2. Convert string to lowercase characters Format: LOWER(string) Give an example: SQ ...

1, Oracle 19c alarm log 2020-01-19 20:40:26.193000 +08:00 Warning: ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE has been deprecated. Warning: ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE has been deprecated. alter database recover managed standby database using current logfile disconnect from s ...

See a friend in the group ask, think of before also met this problem, also do not have a clear answer, so he went online to find the following answer. The conclusion is as follows: boolean type is compiled into int type for use, accounting for 4 byte s. The boolean array is compiled into byte array ...

This series of notes is mainly based on "deep understanding of Java virtual machine: JVM advanced features and best practices version 2", which is the reading notes of this book. jmap command is used to generate memory heap dump snapshot, which is generally called heapdump or dump file. In addition to the jmap command, you can also ...

Custom functions, like scalar subqueries, when the result set (row number N) returned by the main query is huge, the query in the custom function will be accessed N times The only applicable scenario of user-defined function is paging query. Other scenarios basically have potential risks and need to be rewritten. SELECT rrs.o ...