Oracle

1. Intersect operationsReturns the same part of the query result, indicating the intersection of them. SQL> select * from ABC2 intersect3 select * From abc2; 2. Minus operationsReturns the row records that are different from the results of the

When designing a database system, it is important to find out which type of application you are facing. Currently, popular application types include: * online transaction processing (OLTP = online transaction processing) Applications Program *

-- A List Of datafilesselect * from V $ datafile; -- a listing of datafiles along with their associated tablespaces: Select T. name "tablespace", F. name "datafile" from V $ tablespace T, V $ datafile f where T. TS # = f. TS # order by T. name;

Importing and exporting Oracle Data imp/exp is equivalent to restoring and backing up ORACLE data.   The exp command can export data from the remote database server to the local DMP file, and the IMP command can import the DMP file from the local to

1. If the "Regional and language options" option is used after installation, the Oracle service cannot be started normally and the TNS will fail. 2. You cannot assign an IP address through DHCP when installing oracle. You must specify an IP address

OCR is equivalent to the Windows registry. For Windows, all software information, users, configurations, and security are stored in the registry. In the same way, all cluster-related resources, configurations, nodes, and Rac databases are stored in

How can we evaluate the performance of the database to be launched soon? swingbench is the best choice except benchmark factory for databases, which can be described as short and concise and completely free of charge, you don't need to get your

Recently, when using traditional imp tools to import data, a colleague always prompts to receive the skipping table prompt, that is, the table is skipped, rather than being rebuilt. The table object in the target database cannot be imported even if

Normally, when the current control file is lost or the current control file is inconsistent with the control file to be restored, we need to re-create a control file or use unsingBackup controlfile to restore the control file. To put it simply, as

Oracle Data Guard provides one or more slave databases for the production database (a copy of the database ), to ensure that data is not lost when the master database is unavailable or when exceptions occur, and continue to provide services through

ORA-12899 appears, is caused by character set, Chinese occupies 3 bytes in the UTF-8, zhs16gbk occupies 2 bytes, and the source DMP file character set is zhs16gbk inverted data, now to import to the target character set for the UTF-8 library, so

Common database objects 1. Tables: Basic Data Storage set consisting of rows and columns 2. View: logically related data set extracted from the table 3. sequence: regular value 4. Index: Improves query efficiency 5. Synonym: alias User-Defined table

First, two types must be defined. 1. Row Type create Or Replace Type ty_row_str_split As Object (strvalue Varchar2 ( 4000 )) 2. Table typeCreate Or Replace Type ty_tbl_str_split Is Table Of Ty_row_str_split Create Function Or Replace

Http://www.iteye.com/topic/26431 Create a sequenceIntroduction to Oracle Sequence In Oracle, sequence is the so-called serial number, which is automatically increased every time it is obtained. It is generally used in places where the sequence

Recently, due to work needs, we need to optimize the current program. Considering a version in each region, the maintenance cost is too high and the difficulty is too high, it is decided to encapsulate codes of different regions and businesses using

Common Oracle hint usage: 1./* + all_rows */It indicates that the overhead-based optimization method is selected for the statement block, and the optimal throughput is obtained to minimize the resource consumption.For example:Select/* + all + _ rows

I. Introduction: the most important part of database adjustment is to rewrite the SQL code with poor running efficiency. The SQL code after rewriting may be significantly different from the previous one in terms of running efficiency! However, when

1. tkprof is an executable tool for analyzing Oracle tracking files and generating more user-friendly and clear output results. C:/Oracle/ora92/bin/tkprof.exe 2. Full name of tkprof References Http://www.itpub.net/showthread.php? S =

  In actual application, sum () can be used to calculate the total or accumulated values in the group. The specific example is as follows: 1. Create a demo tableCreate Table EMP As Select * from Scott. EMP; ALTER TABLE EMP Add constraint

  Batch Processing is generally used in ETL operations. ETL stands for extract, transform, and load. It is the word of a data warehouse! Similar to the following structure:For X (select * from ...) Loop Process data; Insert into table values