Database Administrator

In project development, we often have complicated business logic. Using the stored procedures of Oracle can greatly reduce the compilation workload of java program code, and the stored procedures are executed on the database, so that the good

First, create a user. Groupadd oinstall Groupadd dba Useradd-g oinstall-G dba-s/usr/bin/csh-d/export/home/Oracle-m oracle Second, create an access point Df-k Mkdir-p/opt/app/oracle/10.2.0 Mkdir-p/opt/app/oracle/doc Chown-R oracle:

During database O & M, it is inevitable that you need to query databases across multiple servers and multiple Oracle instances. For example, you need to check the value of the open_cursor parameter in all current production environment databases to

I. Paging query: 1. Minute by rowidSelect * from t_xiaoxi where rowid in (select rid from (select rownum rn, rid from (select rowid rid, cid from t_xiaoxi order by cid desc) where rownum 9980) order by cid desc;Execution time: 0.03 seconds 2. Score

In actual application development, we have a lot of energy devoted to debugging programs and troubleshooting exceptions. The code developed using the design logic and scenario is often broken by the production data ". Quick locating of Error Data

What is the process of SQL statements in the database? What is the execution order? Before answering this question, let's review: in the Oracle database system architecture, SQL statements are generated by user processes and then transmitted to the

The tkprof program is further described as follows:After the tracking function is enabled, Oracle collects the performance status data of the SQL statements being executed in the tracking session to a trace file. This trace file provides many useful

Oracle unlocking resolves the ORA-00054: Resource busy Error 1. Procedure:-- 1. Get the session_id of the locked objectSELECT session_id FROM v $ locked_object;-- 2. Obtain the sid and serial of the v $ session through session_id #SELECT sid, serial

In 2013, IBM DB2 was 30 years old and was released in DB2 10.5. One of the most eye-catching features was the BLU accelerator, which introduced columnar storage technology into traditional databases, currently, BLU only supports databases of DB2

The TPC (Tracsaction Processing Performance councer) Transaction Processing Performance Association is a non-profit organization that evaluates the Performance of software and hardware in large database systems. TPC-C is developed by the TPC

MyBatis 3.2.6 there are two ways to obtain the auto-incrementing primary key when inserting Take MySQL5.5 as an example: Method 1: Insert into person (name, pswd) values (# {name}, # {pswd }) Method 2: Select LAST_INSERT_ID ()Insert into person

Error locating: SQL>! Oerr ora 01002.01002,000 00, "fetch out of sequence"// * Cause: This error means that a fetch has been attempted from a cursor// Which is no longer valid. Note that a PL/SQL cursor loop// Implicitly does fetches, and thus may

I plan to take a technical note on the Oracle index topic, because today I helped a friend in Shenzhen to perform the rman test and found a ORA-XXXXX error while restoring my raw data. The test results are as follows:Run {Allocate channel category

PostgreSQL supports hstore to store data such as KEY-> VALUE, which is also similar to ARRAY or JSON. To use this type of data efficiently, you must use efficient indexes. Let's take a look at the performance of two different types of indexes for

Implementation: Use php to save the names of all files in a folder to the MySQL database. Note: enter it as A folder A. If this folder contains another folder B, only files in A are not displayed. The source code is as follows: // Function: Save the

Upgrading any software, especially enterprise-level system components, is a very complicated process. The upgrade path, data retention plan, rollback steps, and impact degree of original business functions all require repeated tests and

When we use catalog instead of controlfile as rman repository, the metadata information about the backup will also be stored in controlfil, so that when we use rman, you can use the information in controlfile even if the catalog is temporarily

Ubuntu MySQL automated installation script #/Bin/bashFunction hasDpkg{R = 'dpkg-l | grep "$1 "'If [-n "$ r"]ThenH = 'dpkg-l | grep "ii $1 "'If [-n "$ h"]ThenReturn 1ElseReturn 0FiElseReturn 0Fi} Mysql = mysql-server-5.5"HasDpkg $ mysql R = $?If [$ r-

One day, after the machine was restarted due to power failure and insufficient UPS power supply, it was found that the listener could not be started and an error was prompted: TNSLSNR for Linux: Version 10.2.0.1.0-ProductionSystem parameter file

As a hotbackup tool of innodb, xtrabackup is developed by percona and widely deployed in mysql due to open source, hot backup, and physical backup. The details can be found in the previous discussions. MySQL management-using XtraBackup for Hot