Oracle

What is the difference between an Instance and a database in Oracle? database is actually very simple. database is a medium for storing data. For example, common files are one type. There are several types of data storage in Oracle10G. The first is

Run cmd www.2cto.com 1cd D as an administrator to configure AUTOTRACE for sqlplus: \ app \ Users \ product \ 11.2.0 \ dbhome_1 \ RDBMS \ ADMIN2sqlplus/nolog3connect system4manager5 6 @ utlxplan7create public synonym plan_table for plan_table -- run

The Oracle nvl () and nvl2 () functions introduce a function in the NVL function Oracle/PLSQL. Format: www.2cto.com NVL (string1, replace_with) function: If string1 is NULL, The NVL function returns the value of replace_with; otherwise, the value of

An in-depth understanding of Oracle tables (1): ORDERED and USE_NL ORDERED are good at understanding, that is, they represent sequential join Based on the table following from, from left to right, the table on the left is the driving table use_nl (t1

Data Blocks (Oracle Data Blocks) are the smallest storage unit in Oracle. Oracle Data is stored in Blocks. A block occupies a certain amount of disk space. Note that the "block" here is the "data block" of Oracle, not the "block" of the operating

Create temporary tablespace www.2cto.com SQL code create temporary tablespace test_temp tempfile E for dome1 users: \ oracle \ product \ 10.2.0 \ oradata \ testserver \ test_temp01.dbf 'size 32 m autoextend on next 32 m maxsize 2048 m extent

In pl \ SQL, the process control method block www.2cto.com Java code declare username varchar2 (20); begin select t. ename into username from emp t where rownum = 1; dbms_output.put_line (username); end; 2 use case when in oracle for Java code

Oracle AUTOTRACE statistical information explanation of statistical information in AUTOTRACE: www.2cto.com recursive cals: RECURSIVE read to ensure the smooth execution of user-sent SQL statements, ORACLE must execute some additional statements.

The MEMORY_MAX_TARGET parameter is added to the memory_target summary 11g in oracle 11g. this parameter is as refreshing as it appears for the first time in 10g. Memory_max_target is used to set the maximum memory space occupied by Oracle to OS, and

Add a sequence number for the read data in oracle. When we demonstrate the Report to the customer, the customer sometimes puts it in the first column of the report, can I add a serial No. www.2cto.com? But if I modify the program code, it can be

Oracle batch operation the following code is used for exercises when learning oracle. batch operation can solve the efficiency problem well: www.2cto.com Java code --- create table test2 (id number (6 ), name varchar2 (10) delete test2; select *

Oracle changed Field Type 1. If the field size is changed simply, for example, numeric () --- & gt; numeric ), you can directly alter table name modify (field name numeric () 2). Due to requirements changes, you need to change the field type of a

How to speed up oracle import the traditional imp command, if only data is processed during import, tens of millions of data is simply"Mao Yu", the key is to re-index each table after it imports data. Www.2cto.com Imports one index and one commit,

PL/SQL data type and definition, value assignment Java code www.2cto.com 1. simple variable types and definitions SQL and pl/SQL common variable types: varchar2 (max_length) up to 4000 bytes char (max_length) Max 2000 bytes number (x, y) the

The method for generating and displaying execution plans in Oracle generates an execution plan. After a legal statement is executed, at least one execution plan is generated in the memory, which can be queried from the view v $ SQL _plan. Each

Oracle online redo log recovery (redo log) Non-current online log File fault recovery www.2cto.com 1. ORA-00313 error when starting the database. ORA-00313: open failed for members of log group 1 of thread 1ORA-00312: online log 1 thread 1:

Insert a string containing "&" into the oracle database: www.2cto.com 1. If "&" does not have a string, "&" is a simple character and is processed by character; 2. If & is followed by a string, follow oracle's statement to Operate & as a variable.

During Oracle cross-database query and insertion, data from the GIS_WEICHAI_DATA_1S table in one database must be imported to the GIS_WEICHAI_DATA_1S table in another database. The database servers are all remote ! My implementation method is to use

Basic management of Oracle 10g RAC spfile --- SPFILE www.2cto.com will be created when DBCA is used to create a database --- SPFILE must be created on the shared volume or shared raw device --- all instances use the same SPFILE --- if you manually

ORACLE recycle bin sortingIn principle, the Recycle Bin is a data dictionary table that stores information about database objects deleted by users. Objects deleted by a user are not deleted by the database and still occupy space. Unless the user