Oracle

1. Run sqlplus "/As sysdba" in cmd" 2. SQL> shutdown immediate 3. SQL> startup starts the service. check whether any data file loading error occurs at startup, and remember the error data file number. 4. SQL> alter database datafile 'xx. dbf'

About parent vs child latches. There is no fundamental low level difference between parent and child latches, they are all small regions of memory modified with atomic test-and-set style Opcodes.   You see parent (and solitary) latches from x $

Select name, checkpoint_change # from V $ database; Select name, checkpoint_change # from V $ datafile; Select name, last_change # from V $ datafile; Select name, checkpoint_change # from V $ datafile_header; select. name,. checkpoint_change #, B.

The concept of scan (single client access name) is introduced in the Oracle 11g RAC cluster, that is, the single client access name of the cluster. Scan provides a single host name for the client to access the Oracle database running in the cluster.

The Oracle monitoring index feature allows us to roughly determine whether an index is used. This is because the index is monitored when statistics are collected in Oracle 10 Gb, which is not produced by SQL statements. In the case of 11g, there is

Reasonable creation of strategic indexes for database tables can greatly improve query performance. But in fact, the index we create in daily life is not a strategic index. It is precisely because a large number of redundant or useless indexes

Recently, some netizens are not very clear about the automatic memory management feature of Oracle SGA, probably because the automated management of Oracle 10g SGA translated at that time was quite cool, the following is still a description of this

Oracle db_file_multiblock_read_count is an important global parameter in Oracle, which can affect the system level and sessioin level. It is mainly used to minimize the number of data blocks that Oracle can read at a time in order during table scan.

Similarities and differences between truncate, delete, and dropSame: truncate, delete without WHERE clause, and drop both delete table data.Differences:1. truncate and delete: delete only data. Do not delete the table structure (Definition)The drop

1. b-trees, short for balanced trees, are the most common type of database index. as the name suggests, B-tree is a structure of the Balance Tree. [Note that B indicates the balanced balance, rather than the binary.] B-tree indexes are also the most

Http://wanwentao.blog.51cto.com/2406488/457603 Create and modify users Create userStatement to create a user. When a user connects to the Oracle database, it must be verified. There are three types of authentication in

Oracle Data Security Maintenance I remember a philosopher saying, "The changes of things are inseparable from internal and external causes ." Therefore, Oracle data security is also divided into "internal" and "external. Well, let's start with

4. Select the most efficient table name sequence (only valid in the rule-based Optimizer)The Oracle parser processes the table names in the from clause in the order from right to left. ThereforeThe base table driving table written in the from clause

Create Table T8 (grade number (8); insert into T8 values (100); insert into T8 values (45 ); insert into T8 values (65); insert into T8 values (85); insert into T8 values (90 ); insert into T8 values (60); insert into T8 values (13); commit;

SQL> select dbms_metadata.get_ddl ('Procedure ', 'pro2', 'Scott') text from dual; text -------------------------------------- Create or replace procedure "Scott ". "P RO2" is begin dbms_output.put_line ('wangpeng up'); end; SQL> select

Bulk binding accelerates the efficiency of SQL statements by binding a complete set at a time and processing data in arrays within the PL/SQL block. Two DML statements are used: bulk collect and forall. Bulk collect-used to improve query (select)

--------------------------------------------------------------------------- Set echo off; Set feedback off; Set verify off; Set pagesize 0; Set termout on; Set heading off; Accept username char prompt 'Enter the index Username

Steps for installing Oracle Diagnostics tool: 0. Installation Platform: Linux 3.7 As, Oracle EBS 11.5.10.21. to install the diagnostic tool, you must first install the installation package p361_80_11i_generic.Uncompress, modify the file newprods.txt

Oracle obtains the current date and Date Format Get system date: sysdate ()Format Date: to_char (sysdate (), 'yy/MM/DD hh24: MI: SS)Or to_date (sysdate (), 'yy/MM/DD hh24: MI: SS)Format the number: to_number Note: to_char converts a date or number

Select TCP/IP (Internet Protocol) and click Next, as shown in:     Figure (6) Enter the host name and port number. Note that the host name and port number must be the same as the host name and port number configured by the listener on the database