Database Administrator

1.1 error ORA-600 [kcratr_nab_less_than_odr], cannot start 1. symptom Description: The server storage is powered off, causing the database to go down and start the database again. The database cannot be started normally. The database reports the

The test machine is always powered off, causing Oracle to not restart automatically after restart. manual operations are required, so you can set it to auto-start mode. Operating System: Linux Database: Oracle 10g 1. vi/etc/oratab Find

Obtain the new data table from multiple tables, and then calculate and evaluate the fields of the new data table. Select (Number01.N1/Number02.N2) -- get tow table_fieldsfrom (select count (. field01) as N1 from Table01 A, Table02 Bwhere. field01

Syntax: Test_expression BETWEEN begin_expression AND end_expressionFor example: The database AA table has an AA_RQ field, which is declared, Oracle AA_RQ VARCHAR2 (8 ),SQL Server AA_RQ VARCHAR (8 ),The following two statements have

During lunch break today, I received a request. The system is very slow. From the top view, most processes are zombie processes. Oracle version 11.2.3.x Linux5.6 x86-64 First, we suspect the problems in cron. Use crontab-l, crontab-u oracle-l No

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

Problem descriptionSQL> select dbms_metadata.get_ddl ('tablespace', 'test') from dual;ERROR:ORA-39212: Installation Error: incorrect loading of XSL style sheetORA-06512: In "SYS. DBMS_SYS_ERROR", line 79ORA-06512: In "SYS. DBMS_METADATA_INT", line 73

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: "

There are two ways to load hibernate, one is get loading, the other is load loading, the load is delayed loading, and the dynamic proxy is used. This is not our concern. Let's take a look at the characteristics of one-to-one bidirectional

crs_stat -tName Type Target State Host ------------------------------------------------------------ora.DATA.dg ora....up.type ONLINE ONLINE node1 ora....ER.lsnr ora....er.type ONLINE ONLINE node1

Use MySQL Migration Toolkit to quickly import Oracle Data to MySQLLet's talk nonsense first.I have recently learned some database knowledge. I have been familiar with Oracle and MySQL before, and recently I am very popular with MongoDB

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

The installation of the oracle client is very simple. The key lies in the tns configuration. The rpm installation package I used here is that oracle itself is not open source, which is the easiest to install with rpm. First, download the following

In recent years, the multi-core hardware has been gradually applied to data warehouse products. At present, the main public-core hardware includes the multi-core CPU represented by Intel SCC, the multi-core coprocessor represented by Intel Zhiqiang

1 using () is used for join queries on two tables. The column specified by using () must exist in both tables and is used as the join condition. Example: select. *, B. * from a left join B using (colA); equivalent to: select. *, B. * from a left

Simple Application of triggers A trigger is a special stored procedure. The difference is that the stored procedure needs to be called, and the trigger does not need to be called. During certain operations, the trigger will automatically execute.

Http://blog.csdn.net/chszsI. OverviewApache CouchDB and CouchBase NoSQL databases are both open-source and free NoSQL document-type databases, and JSON is used as the document format. The similarities between Apache CouchDB and CouchBase are

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

References: Http://patrick-tang.blogspot.com/2012/06/redis-keepalived-failover-system.html Http://deidara.blog.51cto.com/400447/302402 Http://my.oschina.net/guol/blog/182491 Http://shiguanghui.iteye.com/blog/2001499 Background Currently,

The current status is dg1 as the master database, and the slave database is dg2.First check the status of the Master/Slave database:Dg1 SQL> select name,database_role,OPEN_MODE,SWITCHOVER_STATUS from v$database;DATABASE_ROLE OPEN_MODE SWITCHOVER_