Oracle

In csdn, it helps others write a simple trigger to update data, which involves several problems.   Create or replace trigger tri_aAfter insertOn test11DeclarePragma autonomous_transaction; ---- after declare) indicates free transaction

Oracle optimizer has two optimization methods: Rule-Based Optimization (RBO) and cost-based optimization (cost-based optimization, (for short, CBO). In oracle8 and later versions, the CBO method is recommended for Oracle strong columns.RBO mode:

1. view the table space name and size. Select T. tablespace_name, round (sum (Bytes/(1024*1024), 0) ts_sizeFrom dba_tablespaces T, dba_data_files dWhere T. tablespace_name = D. tablespace_nameGroup by T. tablespace_name; 2. view the name and

From: http://blog.csdn.net/zhiguo2010/article/details/5737492 In Oracle, the Null String is considered null, and any value compared with null is null. In this way, an exception occurs when comparing two strings. See the following example: DeclareI

For a long time, I have been using ms SQL Server/Access database, through. Net Access MS home things almost never encountered any trouble. Recently, I used oracle as a database in my project. I learned some things about. Net accessing Oracle and

You can specify the returning statement in the DML Statement of oracle. The use of returning statements can simplify PL/SQL programming in many cases. It is not intended to explain the use of the returning statement (in fact, it is very simple to

Today with PL/SQL to connect to a database old report ora-12541: TNS: No listener error. Solution: Refer to the SQL * Plus User's Guide and reference for more information.[Oracle @ vserever75 ~] $ Sqlplus/nolog SQL * Plus: Release

There are several solutions: the first one. restart the server to fix the listener. log on to the database, sqlplus/As sysdba; SQL> shudownsql> startup # startup start # shutdown to close # LSNRCTL stop to close the service, execute close listener #

Cursor Learning 1. What is a cursor:A cursor is a swimming cursor.Description in the database language: the cursor is the object mapped to the position of a row of data in the result set, with the cursorYou can access any row of data in the result

Recently, I am engaged in C-language connection to Oracle and DB2 databases. Now I will summarize the article on C connection to Oracle:   Connect to the Oracle database in C language.There are two ideas and purposes Idea 1)Local Environment: Ubuntu

Method 1:SQL> Create Table B as select 1 ID from dual connectLevel Method 2: SQL> Create Table A (ID INT ); Table created. SQL> insert into a select 1 from dual connect by level 100 rows created. Method 3: Create Table test_big as select * From

Choose from csdn http://search.csdn.net/Expert/topic/2280/2280860.xml? Temp = 20179436e-02 comments from jcc0128 in Forum [Delphi + Oracle report solution (1)] Calling the stored procedure of Oracle in Delphi (two types of data with return cursor

43. Convert (C, dset, sset)Convert the source string sset from one language character set to another destination dset Character Set SQL> select convert ('strutz', 'we8hp ', 'f7dec') "Conversion" from dual; Conver------Strutz 44. hextorawConverts a

Oracle9i introduces the merge command. You can execute the inserts and updates operations on a table in an SQL statement at the same time. the merge command selects rows from one or more data sources to update or inserting to one or more tables. in

Io OptimizationIn the case of massive data, more than 80% of database performance problems are related to Io, So I/O optimization is an important task throughout the whole process of massive database management.I/O optimization involves a wide range

How to define the cursor typeType ref_type_name is ref cursor [return return_type];Declare cursor variableCursor_name ref_type_name;From the technical bottom layer, the two are the same. Common PLSQL cursor is "static" in definition. While ref

After a long period of learning to create Oracle tablespaces, I would like to share with you that you will certainly have a lot of gains after reading this article. I hope this article will teach you more things. 1. First query free space 1

Recently, considering the usage of temporary tables in the database write stored procedures   It is still unclear how the database is processed, whether it is consistent with the SQL server processing method.   Are there any problems, such as

Write an insert statement today to directly extract the data in a table and insert it into another table. The result syntax is missing. Searching for half a day. It's an idiot. Let's record the found syntax first...Set feedback off;Set pagesize

July 12. 2004. I met a couple of time the problem. The nearest time was last week. Solution-from Metalink note. Problem description:================================Running svrmgrl (or any other Oracle tool such as SQL * Plus) on an IBM AIX