Oracle

Why Does oracle not use indexes? Today is. Let's summarize the reasons why oracle does not use indexes. Take notes while learning. First, the number of rows varies. There is a num_rows field in the view user_tables. This field records the number of

1. Capture representative SQL workloads1.1. Create an SQL adjustment set (STS)SQL> exec dbms_sqltune.create_sqlset (sqlset_name => 'SQL _ test', description => '11g spa test ');PL/SQL procedure successfully completed.1. 1.1. Load the SQL statement

Select DISTINCT (t. f_resume_id | t. f_resume_status), t. f_resume_status, t. f_resume_status, t. f_recruit_channel,T. f_small_channel_idFrom css. T_RESUME_INFO t where t. f_resume_status in (80011,80012) Multiple distinct fields. Of course, the

When diagnosing the lock issue, you need to find the owner and the blocked person. It is often very troublesome. If you have no accumulated scripts, You need to manually query many tables, such as v $ lock, v $ process p, v $ session s, and v $

This section briefly introduces the execution process of various oracle connection methods. The pseudocode is derived from pro oracle SQL.Nested loop:Select empno, ename, dname, locFrom emp, deptWhere emp. deptno = dept. deptnoFor each row in

Today is, I plan to make a special technical note of oracle index, because today I helped a friend in Shenzhen to do the rman test, when restoring my original data, found that there is a ORA-XXXXX error, the test results are as follows:Run {Allocate

1. Preface Recently, due to project requirements, the employee's working group needs to be returned to the front-end. However, in the database, the employee's working group Id is included in a field (separated by commas ), this does not meet the

Today, I forgot my password for an account in the test database. After a dozen attempts, I started to prompt: ERROR:ORA-28000: the account is locked This means that the account is locked. It may be because the user's resource settings limit the

Create JXDW2014 User Password JXDW and grant DBA permission Enter the sqlplus password in the Start Menu, as shown in the following code: Other permissions include: Grant unlimited tablespace to JXDW2014; -- grant unlimited tablespace Grant

Databases are the soul and brain of business. As the core IT business module, there is no doubt about the importance of databases. After the management database is deployed in the early stage of the system, during the continuous operation of the

I. Problems FoundSome ghost programs will clear some of the Oracle registration table information or delete some of the .exe files in the oracle's bincatalog, resulting in the database cannot be started. Next, let's analyze the most common problems.2

We will mainly introduce the example of Oracle job usage today. We hope that the following Oracle job instances will be useful to you in your practical application. If you are not familiar with Oracle job usage, you can browse the following articles.

IOPS (Input/Output Operations Per Second) is the number of read/write (I/O) Operations Per Second. It is mostly used in databases and other occasions to measure the performance of random access. The storage IOPS performance is different from the

Applies to: Oracle Universal Installer-Version 11.2.0.1 and laterOracle Database-Enterprise Edition-Version 11.2.0.1 and laterOracle Database-Standard Edition-Version 11.2.0.1 and laterInformation in this document applies to any platform. Goal How

// Data integrity, business and logic rules can be implemented using three methods: Constraints, triggers, and applications (processes and functions)// The constraints include not null, unique, primary key, foreign key, and check.// A table can have

1. TRUNC Function The Oracle TRUNC function can intercept numbers and date types: 2. TRUNC truncated numbers The TRUNC (number) function returns the n1 truncated to n2 decimal places. If n2 is omitted, n1 is truncated to 0 (that is, all decimal

1. view the database version SQL> select * from v$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production PL/SQL Release 11.2.0.1.0 -

-- ***************** View the tablespace size *****************Select upper (F. TABLESPACE_NAME) "tablespace name", D. TOT_GROOTTE_MB "tablespace size (M )",D. TOT_GROOTTE_MB-F. TOTAL_BYTES "used space (M )",TO_CHAR (ROUND (D. TOT_GROOTTE_MB-F.

Multiple methods for starting or disabling Oracle databases There are many ways to start and close oracle. Here, we only provide three methods: L SQL * plus L OEM Console L Windows Console 1. Take SQL * plus as an example: A. Prepare First, we use

1.Oracle server Character Set QueryCopy codeThe Code is as follows:Select userenv ('language') from dual; Server Character Set Modification: Start the database to RESTRICTED mode and make character set changes:Copy codeThe Code is as follows:SQL>