oracle study guide

be cached for the reason. So who is more efficient for part_query_p and part_query? In two groups of experiments, part_query_p and Part_query were the first algorithms to be executed. The experimental data of part_query_p and Part_query were removed from two sets of experimental results, and the effect of cache was almost completely excluded. Two algorithms, each hit 9 times. Explain the efficiency of the equivalent. However, it is obvious that the part_query has a higher hit ratio (greater th

Recently, oracle has been used, so you should study the basics and sort out the materials, hoping to help your friends in need. Recently, oracle has been used, so you should study the basics and sort out the materials, hoping to help your friends in need. 1. multiline Functions, also known as Group Functions and Agg

Oracle Study--oem Login Error system environment:Operating system: Windows 7Database: Oracle 11gR2"Certutil-setreg chain\enableweaksignatureflags 8", will prompt:650) this.width=650; "src=" http://blog.itpub.net/attachment/201402/25/25116248_13932987099U9s.jpg "width=" 562 " height= "261" style= "border:0px;font-size:14px;line-height:26px;white-space:normal;font

Tags: OracleOracle study--aix RAC under OCR disk failure (PROT-602) ******************************************************************************** Welcome to AIX Version 5.3! ** ** The README file In/usr/lpp/bos for information pertinent to ** This release of the AIX Operating System. ********************************************************************************Failure Phenomena：[[email protected]/] #crsctl ch

previous: oracle DBA Study Notes-control files RedoLog Files Redo log files record the changes made to the database (or changes to transactions) in the form of redo records, including the execution of DMLOrDDLStatement modification to the database,It also includesDBAModify the database structure,Redo log files also need to be reused. Log File writing principles:1.Write order must strictly fol

operations-single-line DML and bulk DML will run faster, and single-line processing proceeds mainly from reduced index maintenance by 10 times times;7.1% of applications are transparent. Similar to OLTP compression, the main advantage is that it is completely transparent to the application. All other Oracle features will work with IN-MEMORY option, including partitioning, indexes, text indexes, without explicit data types or storage type restrictions

created.sql> CREATE DATABASE [email protected] to test identified by test using ' dmdb ';The database link was created.sql> SELECT * [email protected];D-Xsql> SELECT * [email protected] @link1;D-Xsql> SELECT * [email protected] @link2;D-X That is, add @ plus an identity after global_name. This enables you to create multiple databases that are linked to the same target library. In addition, when creating a database link, you cannot create a link to another schema because the database link has a

According to my recent study on Oracle databases, I have learned more about Oracle and hope to help some new Oracle users. Oracle provides several simple data types, Unlike SQL server. Common Oracle data types include char, varch

Oracle DataGuard Study--dataguard failover caseOracle DG (Dataguard) is now a common database ha configuration policy. By implementing physical Standby and logical Standby, the data redundancy tolerance mechanism can be realized. There is no fast backup support environment when there is a major failure in the main library and no support for the service. in Dg switchover and failover dg The core of implem

Oracle Study Notes-NVL () function usage skills, learning notes-nvl 1. Rules for alias columns: special characters (except # $), numbers, and spaces must be added with double quotation marks; Chinese characters can be added with double quotation marks without double quotation marks; as keywords can be omitted. -- Query the employee name, employee ID, and employee's work.SELECT empno AS "employee ID", ename