Oracle

The difference between writing SQL statements directly in PL/SQL and using the execute immediate method is that when executing SQL statements in PL/SQL, you can directly write SQL statements or splice an SQL statement into a string, as shown below:

Quickly install Oracle Database 10 GB on RedHat AS3: Su-root Dd if =/dev/zero of = tmpswap bs = 1 k count = 900000 Chmod 600 tmpswap Mkswap tmpswap Swapon tmpswap Check the tmp space and run the command: $ df/tmp If the temporary space is

I. Basic commands 1. Get help $ Exp help = y $ Imp help = y 2. Three ways of working (1) Interactive Mode $ Exp // enter the required parameters as prompted (2) Command Line $ Exp user/pwd @ dbname file =/oracle/test. dmp full = y // enter the

Using rman to create standby is quite simple and the master database does not need to be stopped. This experiment demonstrates the process of using Rman for Hot Backup and then restore to create the standby database. 1. Demo Environment[Oracle @

1. oracle optimizer======================================Oracle has three OptimizerRULECOSTCHOOSEThe OPTIMIZER_MODE parameter is used to set the optimizer type. It is a selective optimizer by default and is both a CHOOSESQL> show parameter OPTIMIZER_

How to find the number of tables locked in oracle: Select B. owner table_owner, B. object_name, c. username, c. sid, c. serial #From v $ locked_object a, dba_objects B, v $ session cWhere a. object_id = B. object_id and c. sid = a. session_id;In

Oracle Database-Table connection method (hash, merge, nest loop) nested loop is a good choice for a small subset of connected data. The nested loop is used to scan a table. Every time a record is read, it is searched in another table based on the

Oracle11gr2 hard limit installation error solution 1. hard limit error Hard Limit: maximum open file descriptors-This is a prerequisite condition to test whether the hard limit for "maximum open file descriptors" is set to at least 65536. expected

ORACLE table partition and partition index Partition Table, partition index, and global index: When a table contains more than 20 million data entries or occupies 2 GB of space, we recommend that you create a partition table. Create table ta (c1 int,

Oracle string comparison --- null in ORACLE, the NULL String is treated as NULL, and the comparison result of any value and NULL is null. In this way, an exception occurs when comparing two strings. See the following example: DECLARE I VARCHAR2 (10):

ORA-02069: global_names parameter must be set to TRUE for this operation database suddenly has the following error: ORA-02069: global_names parameter must be set to TRUE for this operationhttps: // forums.oracle.com/thread/472482 answers to this

The backup and recovery parameters of the parameter file include initsid. ora (Text parameter file) pfile (Text parameter file), spfile (binary parameter file) Three pfiles and spfile can be converted to each other (copy ): create spfile = 'path'

[Oracle]-[implicit commit]-functions of normal and abnormal exit on commit create table my_objects as select * from all_objects; commit; select count (*) from my_objects; COUNT (*) ---------- 8587 delete from my_objects; 8587 rows deleted. exit: Log

Three methods of Oracle database backup and recovery Oracle database has three standard backup methods: Export/Import (EXP/IMP), hot backup, and cold backup. Exporting spare parts is a logical backup, while cold backup and hot backup are physical

NULL in subquery the subquery returns a single row, multiple rows, and null value. It is applicable to the comparison operators of single-row subqueries: =, >,=, SQL> select last_name,department_id from employees where department_id is

Oracle synonym loop chain problem solution [SQL] 1. First check whether there is a loop synonym: select * from dba_synonyms where table_owner = 'test' and synonym_name <> table_name; no record 2. Then query the database objects with no synonym

ORACLE-related syntax-subprograms and packages (package, function, procedure) Summary: subprograms are named PL/SQL blocks that can contain parameters and can be called as needed at any time. PL/SQL has two types of subprograms: process and function.

[Oracle] Data Guard series (6)-role conversionThe core function of DG is to provide high-availability Disaster Tolerance. Therefore, the role conversion content described in this section is the most important part of DG. Role Switching between

This article introduces how to solve the problem that http: // localhost: 5560/isqlplus cannot be opened in oracle. If you encounter problems, refer to this article. I am going to review oracle today. oracle was previously installed. I re-installed

Many of my friends who use mysql limit for paging to oracle do not know how to write paging. In fact, oracle paging is similar to mssql paging. Next I will introduce oracle paging statements. Simplest use The Code is as follows: Copy