Database Administrator

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

Speaking of DBA, the full name is Database Administrator, not Doctor of Business Administration. Do not misunderstand it. That's a world of difference! Even so, many people still think that there is a mysterious veil, an uncertain, and a garlands

Zookeeper impdp fail with ora 31623 FYI: Data Pump import and export job use queues, streams and java objects. If we see any job component is invalid (e.g. dbms_java, queue dictionary scripts not run, rdbms/admin/utlrp. SQL not run) we may see the

Testing TPC is a serious task. It is just for entertainment. Don't confuse it with the TPC Committee's high-end reports.1. First find a less standard TPC-C Testing ToolIt seems that this thing of Percona MySQL is used more people:

The Sesame database uses Java APIs to query and modify data.1. query data to obtain the queried data (through SPARQL) public static void testQuery() {try { RepositoryConnection con = repo.getConnection(); try { String queryString = "PREFIX rk: "

How to delete archived logs for a certain period of time Eg:RMAN> SQL 'alter session set nls_date_format = "YYYY-MM-DD "';SQL statement: alter session set nls_date_format = "YYYY-MM-DD"RMAN> delete archivelog from time "2012-12-01"

Enables users to write quota in the tablespaceThe user on the tablespace to create tables, insert data these basic operations, sometimes will also report ORA-01950: no privileges on tablespace 'system', then, how to do it at this time?9i library,

When the built-in functions provided by Hive cannot meet your business processing needs, you can consider using user-defined functions (UDF: user-defined function ). Currently, Hive only supports writing udfs in java. If you need to use another

This is also based on our first test in English. For the first test, the number of people tested is 100, and the valid data is. some people say that listening is normal. No problem. Some people say they have tried it out. It took five minutes for

If a colleague reports a case, he or she wants to add permissions such as viewing, executing, debugging, replacing, and debugging the package. Next I sorted out what permissions can be done.First, we have the following three dimensions for this type

Background: The monitoring script SHELL finds it troublesome to log on to the server every day, and the number of servers is growing. Originally, I wanted to use the SendMail function of the system, but the company said it was not safe. You have to

Recently, we tried to upgrade our company's DataWit Business Intelligence System ETL tool to test the support capability for Oracle Database 12c. Therefore, we need to establish a test environment. I remotely install the Oracle DB 12c database to a

How many stages are there in Database Design? Strictly speaking, there are more than three stages. Today we will only discuss three of them. Concept Design, logical design, and physical design. First, we need to clarify a few questions. Why should

I. Stored Procedure PurposeIt is used to execute an operation, named PL/SQL block, and can receive passed parameters and be called.Brief IntroductionNamed PL/SQL BlockAcceptable parametersCan be called repeatedlyUsed to perform an operationStored

Anyone familiar with MySQL may know that MySQL has an "insert ignore" syntax to ignore existing records. PostgreSQL does not currently provide such syntax, but it can be replaced by other methods.The following shows the sample table structure and

1. External Connection select * from T_N left join T_S on T_N.id=T_S.id   select * from T_N right join T_S on T_N.id=T_S.id

(gdb) qThe program is running. Quit anyway (and detach it)? (y or n) yDetaching from program: /u01/app/oracle/product/11.2.0/bin/oracle, process 7376 [oracle@mydb ~]$ gdb $ORACLE_HOME/bin/oracle 7376GNU gdb Fedora (6.8-27.el5)Copyright (C) 200

The previous tasks involving oracle regular backup were completed at the operating system level. The following uses oracle task scheduler to regularly perform oracle backup. For detailed steps, see: 1. the backup statement/oracle/bak/fullbk.txt is

When I first walked into the door of the company in the morning and walked to my desk, my development colleagues worried and said, "You can come! Me: What happened? Developer: XX database is dead! Me: Very surprised! This database has been running

MySQL5.6 has been out for a year, and has an understanding of its new features. It is also basically stable. When the minor version is 5.6.20, you can consider upgrading the online database version. For more users to upgrade in the future, I have