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Author: threedaymanSource: Hang Seng LIGHT cloud communityBasic conceptsdatabaseoracle database is the physical storage of data. Including data file ORA or DBF, control file, online file, log file and parameter file. oracle has only one database, which is managed by users. The process of creating a database in mysql database is to create a data ...

1. Scenario Display Regular expressions and corresponding functions are the same in oracle and mysql. Introduction to regular expression symbols: '^' Matches the start position of the input string, used in a square bracket expression, where it indicates that the character set is not accepted. '$' Matches the end of the input string. If set Re ...

The table.sql file used for testing was uploaded to my resource library... If you want to use it, you can use the following three tables for testing only. The specific contents of each table are as follows: Department table Area table Employee table There are too many specific contents. Some contents are displayed here 1. Basic quer ...

The block linked list of Oracle 21c is the most concerned feature, but there is another small feature rarely mentioned, that is Immutable tables - Immutable tables.The block linked list was introduced in 21c and then transplanted back to 19.10. The immutable list was introduced into Oracle 21.3 and 19.11 at the same time. Therefore, it can be c ...

  Item Source System Target System Platform CENTOS7 - 64bit CENTOS7 - 64bit Database Oracle 11.2.0.4 Oracle 11.2.0.4 Character Set AL32UTF8 AL32UTF8 ORACLE_SID cd sz Listener Name/Port LISTENER/1521 LISTENER/1521 Goldengate User ogg ogg   1. Install OGG and create a directory (both sou ...

1, Definition of Oracle collection Set is a data type in Oracle, which stores a group of data with the same data type. 2, Composition of set Consists of subscripts and values. The types of subscripts include numeric types (integer type, pls_integer and binary_integer) and string types. The types of values are all types in the database (b ...

1. Course introduction first day: 1.Oracle concept and installation 2. Basic query 3. Condition query 4. Functions in Oracle the second day: 1. Multi table query (mysql also has the same concept, different syntax and important aspect) 2. Sub query (it also exists in mysql, with the same concept, different syntax and important aspect) on th ...

Oracle advanced query Advanced query is widely used in database development. This paper introduces Oracle advanced query from three aspects: grouping query, multi table query and sub query. Grouping query Grouping query is to group according to certain rules. After grouping, data will be aggregated, and aggregation function is required. Howe ...

Oracle create table Oracle table is the core of Oracle database and the logical basis for storing data. Oracle table is a two-dimensional data structure. The data with column fields and corresponding columns constitute a data storage structure. You can simply look at a two-dimensional table in rows and columns. Columns represent Oracle columns ...

This experiment comes from Oracle developer performance lesson 2: Module 2: What are Database Statistics? It is a repetition and interpretation of this experiment. First, create two tables for the experiment, namely bricks and colors, and generate statistical information: -- According to document Database Reference，statistics_level The defau ...