Programmer Think

introduction    when I first started the project, I had little development experience. In case of problems, I just needed to query the results. As for the efficiency of query, I may not have much consideration. It's OK when there is little data. As soon as there is more data, the efficiency problem will appear. Every time when the que ...

DBLink implements the method of importing other Oracle database instances without dropping backup files background Companies often need to back up database instances from other servers Previous operations generally require that the backup source server use expdp to export the source dump file Copy to the target server, and then import the exp ...

In work, we delete data or database by mistake. Do we have to run away? I don't think so. Programmers must learn to save themselves and retrieve the data unconsciously. In MySQL database, we know that binlog logs record all our operations on the database, so binlog logs are a sharp tool for us to save ourselves. Today, taking MySQL databa ...

pojo: public class User { private Integer id; private String name; private String pwd; setter and getter.... } Database: 1. Gets the value of the self incrementing primary key Mapping file: <!-- UserMapper Interface public void addUser(User user); --> <insert id="addUser" parameterType="com.workhah.pojo.Us ...

Oracle Global Temporary Table is hereinafter referred to as GTT (Global Temporary Table), and Private Temporary Table is hereinafter referred to as PTT (Private Temporary Table). The main differences between GTT and PTT are as follows: GTT is earlier. GTT is a feature of 8i and PTT is a feature of 18c.The data of GTT and PTT are session priva ...

Computer information system Definition: data intensive, man-machine interactive computer system with the main purpose of providing information services Features: large quantity, lasting, sharing and providing a variety of services Structure: 1,Resource Management(DBMS and DB All on this layer) Various data information and resource manage ...

Please read carefully and refer to the README document for the latest steps, processes and related requirements for the overall upgrade of Oracle 19c rac cluster from 19.3 opatch to 19.10. 1, View the current database patch version col ACTION for a8 col status for a15 set line 999 col ACTION_TIME for a30 col DESCRIPTION for a50 SQL> selec ...

Oracle 1. Oracle architecture 2. Storage structure of Oracle It is divided into physical storage structure and logical storage structure, as shown in the following figure: Physical storage: Control file (. ctl), log file (. log), data file (. dbf/.ora) Data file: Data file is the physical storage unit of the database. The data of the dat ...

1. Use Navicat Premium to connect oracle and mysql To connect to local oracle, you need to download the corresponding oci file OCI download address Extract the downloaded oci file, Navicat premium - > tools - > Options, and find the extraction address of oci configuration oci file 2. Problems encountered in migration and Solutions 1. T ...

Due to the learning needs, I will start to learn the basic knowledge of database and the preparation and use of SQL statements from today. Therefore, I record my learning process here to urge myself, consolidate the knowledge I have learned, and hope to help more introductory students. 1. Establish database create database db_name;//db_name i ...