Oracle

When diagnosing the lock issue, you need to find the owner and the blocked person. It is often very troublesome. If you have no accumulated scripts, You need to manually query many tables, such as v $ lock, v $ process p, v $ session s, and v $

Copy codeThe Code is as follows:Import java. SQL. CallableStatement;Import java. SQL. Connection;Import java. SQL. DriverManager;Import java. SQL. ResultSet;Import java. SQL. SQLException;Import java. SQL. Statement;Public class TestPage {Public

The following describes how to use a connection pool to connect to a database on the Tomcat server.1. Modify the web. xml file:Copy codeThe Code is as follows: project index.html index.htm index. jsp default.html default.htm default. jsp

All oracle files may be faulty or lost due to misoperations! These problems are often the most frustrating! Of course, for a person who has a deep understanding of the oracle architecture, the problem is not very difficult! Next, let's talk about

In the Oracle database, the SOUNDEX function returns the voice representation of the string parameter, which is useful for spelling different words, but has the same pronunciation as some others. Syntax of the SOUNDEX function: SOUNDEX (string)

Similar to the installation of Oracle12c, I have done this tutorial to communicate with colleagues. The tutorial content includes:1. Detailed installation manual, 60-page Word Document2. Detailed installation script to simplify installation

Today is, I plan to make a special technical note of oracle index, because today I helped a friend in Shenzhen to do the rman test, when restoring my original data, found that there is a ORA-XXXXX error, the test results are as follows:Run {Allocate

Create JXDW2014 User Password JXDW and grant DBA permission Enter the sqlplus password in the Start Menu, as shown in the following code: Other permissions include: Grant unlimited tablespace to JXDW2014; -- grant unlimited tablespace Grant

Databases are the soul and brain of business. As the core IT business module, there is no doubt about the importance of databases. After the management database is deployed in the early stage of the system, during the continuous operation of the

We will mainly introduce the example of Oracle job usage today. We hope that the following Oracle job instances will be useful to you in your practical application. If you are not familiar with Oracle job usage, you can browse the following articles.

IOPS (Input/Output Operations Per Second) is the number of read/write (I/O) Operations Per Second. It is mostly used in databases and other occasions to measure the performance of random access. The storage IOPS performance is different from the

In the CBO mode, the optimizer determines whether to use full table scan or index. The optimizer compares all possible methods and selects the lowest cost method. Using SQL Tuning Advisor and SQL Access Advisor, you can call the optimizer in

1. Create a database mybase in oracle and a new users table. The table has two fields: id: auto-increment and name. The steps are omitted. 2. Create a java project and import two jar packages: classes12.jar and mybatis-3.0.4.jar. 3. Create a package

I wish you all the best in 14 years. Show the date and the week of the day:SQL> select to_char (sysdate + level-1, 'yyyy-mm-dd') dt,To_char (sysdate + level-1, 'aws') weeks from dual connect by level DT WE------------2014-01-03 012014-01-04 012014-01

The first thing we think of is creating an index. Creating an index can multiply the query efficiency and save time. However, if the data volume is too large, simply creating an index at this time will not help. We know that if we count queries in

1. Memory Management, add at the end of the file/Etc/sysctl. conf fs. aio-max-nr = 1048576 fs. file-max = 6815744 kernel. shmall = 2097152 kernel. shmmax = 536870912 kernel. shmmni = 4096 kernel. sem = 250 32000 100 128 net. ipv4.ip _

In one case, the following error message is found in the trace file. D: \ oracle \ product \ 10.2.0 \ admin \ dbserver \ udump \ orcl_ora_5888.trc Corrupt block relative dba: 0x09848269 (file 38, block 295529) Bad header found during buffer

Select distinct --, -- from --; // query the specified row, which is not repeated.Set timing on; // display the start timeSelect count (*) from --; // countSelect -- ''-- from --; // alias of the name displayedNvl (comm, 0) // If comm is not empty,

Oracle query result set, random sortingCopy codeThe Code is as follows:Select * from table1 order by dbms_random.value (); MySQL randomly queries a record:Copy codeThe Code is as follows:-- The following query statement is highly efficient. Do not

This article describes how to prove that a recursive session exists and explains why it is not displayed in the v $ session. If you need to know it, go to the reference page. When we use the database, we sometimes encounter similar situations. My