Oracle

1. Log in to Oracle as DBA2, create user, users-->new ... Enter user name and password3, give Connect/resource role4, give the user permissions on the view operation the following 3 sentences SQL--Create View permissions, generally on the internet

simple usage of substr functions in OracleSUBSTR (string, intercept start position, intercept length)//return intercepted wordsubstr (' Hello World ', 0, 1)//return result is ' H ' * start with a string of length 1 from the first charactersubstr ('

ALTER DATABASE Character set Internal_use ZHS16GBK;ALTER DATABASE CHARACTER SET zhs16gbk;Oracle Modify character encoding 11 Opening a Command Window 22 View current character encoding 33 Executing the command 4Oracle Modified character encoding

The approximate steps are as follows:(1) Copy the JDBC Driver jar package file (Ojdbc14.jar) from Oracle to the JMeter Lib directory.(2) Running Jmeter.bat(3) Create thread Group: Right-click Test Plan, add->threads-> thread Group(4) To establish a

Beginners SSH Framework, in the online search for resources for reference study, found that in addition to the learning of MySQL, most also use Oracle. In order to better use the database in the future, specifically on the Internet to find some

Backup:Defined:The process of copying a database to a dump device.Dump device:The tape or disk where the database copy is placed.Backup of the original database:A copy of the database stored in a dump device.Classification:Physical and logical

One, concurrencyConcurrency is the most important feature of an OLTP database, but concurrency involves the acquisition, sharing, and locking of resources.Mysql:MySQL is a table-level lock-based, the granularity of the resource lock is very large,

Current Oracle Database Best Test Tool otest* Otest is used for Oracle database testing, optimization, and monitoring software.* Otest is available free of charge to Oracle customers and the vast majority of DBA engineers. Developed by the original

Manage Oracle databases, from the simplest startup and shutdown databases.If Oracle is running under a Linux system, first of all, to connect to a Linux system,The SECURECRT is an ideal tool for connecting remote systems that run Windows, UNIX, and

The goal of Oracle indexing is to avoid full table scans and improve query efficiency, but in some cases it is counterproductive.For example, there are millions data in a table, indexes a field, but there is no improvement in query performance,

One, the string functionLower (string) lowercaseUpper (String) uppercaseInitcap (String) Capitalize first letterConcat (column 1, column 2) two-column mergeLength (string) by wordLENGTHB (String) in bytesLENGTHC (string) length of Unicodesubstr

Oracle provides a sequence object that provides self-growing serial numbers from the system, typically used to generate the self-growing primary key or ordinal of a database data record.Here are some common operations on sequence generation,

Do not know what to do, the data sheet locked, unable to update.Baidu has a variety of methods, summarized as follows.Check the locked table (two sentences are available):SELECT * from v$session T1, V$locked_object T2 where t1.sid=t2.

Tag: T-SQL statement cannot execute under stored procedure call instead of Div Note command executionWhat is a stored procedure? A stored procedure is a named PL/SQL program block, which is a block of code that consists of some T-SQL statements that

1 --Querying table Information2Xxx_tables--contains basic descriptive and statistical information for a table3Xxx_tab_columns--contains descriptive and statistical information for the columns in the table4Xxx_all_tables--contains all the

What are the available commands for 1> Oradebug? Log into the database as SYSDBA, through Oradebug help can see oradebug commonly used commandsSqlplus/as SYSDBAOradebug Help 2> Tracking Current session informationOradebug Setmypid--Track current

The previously responsible project was useful to Oracle, and Oracle DBA gave some advice, tidied it up, wrote it down and made a memo.Database Requirements Analysis:1. The database name created is mailDB, and the character set is UTF8.2. Provide a

Copying tables-- Copying Tables Create Table as Select * from Product-- duplicate table structure no data Create Table as Select * from where 1 = 2Following a condition that is not established in the where, only the structure of the table is

Oracle default Listener Port 1521, a common scanner is usually detected by the 1521 port is open to detect the presence of Oracle services, if the modification of the default listening port to some extent can improve the security of the database and

Read consistency: Oracle guarantees read consistency through multiple versions and flashback mechanisms. Ensure that queries are consistent from one point in time. In Oracle, the version of the system modification is controlled primarily by the SCN