Database Administrator

Question: Recently, a set of database orders by customers often suffer from high data and business pressure. When RMAN performs full backup or Incremental backup, a large amount of business needs to be processed at this time, system resources will

Use JDBC to update and query database instances:   PackageOrg. Oracle. insert; ImportJava. SQL. Connection; ImportJava. SQL. DriverManager; ImportJava. SQL. ResultSet; ImportJava. SQL. Statement;

After configuring nodes in Specify Cluster Configuration, click next: The specified nodes are not clusterable INFO: Query Returned: Null This is because ssh is not properly configured for trusted authentication: Although trusted authentication

The following error occurs when I log on to the system. If I run any command during package expansion, an error is returned: Last login: Thu Nov 10 08:32:12 2011 from 134.224.55.126ERROR: ld. so: object '/etc/libcwait. so' from/etc/ld. so. preload

Today, I encountered a listener startup problem. The problem was that there was no problem when Oracle was installed on the original machine. After the machine name was changed, the listener could no longer be started, the problem is located due to

When importing historical data, there is a list query, and the query is normal before the data is imported, but the query error occurs after the data is imported, debug debugging finds that there is a to_number field in the SQL statement that has

In our actual application, we often need to deploy configurations between data and source code. So I am writing this blog for you to exchange and learn. The connection to Oracle databases is cumbersome. At the beginning, you cannot afford to suffer

As An ORM framework, Hibernate needs to consider loop and SQL statements. It is mainly reflected in session usage, lazy usage, outjoin usage, and batch-size usage. The following details 1. For session usage, a tool class should be provided to

Keywords: Hongqi Asianux3 + Oracle 10g R2 for Linux x86-64 1. Receive a consulting phone number in the morning: Oracle cannot be started in Linux. We will try to solve the problem at the site in the afternoon. 2. After arriving at the site, learn

Here is a test of rman backup and recovery: The database is in the mount status and cannot be connected by other users:SQL> select status from v $ instance; STATUS------------MOUNTED SQL> conn scott/OracleERROR:ORA-01033: ORACLE initialization or

IN Operator SQL statements written IN are easy to write and understand, which is suitable for modern software development. However, SQL statements using IN always have low performance. The following differences exist between SQL statements using IN

Oracle-view, sequence and Index Goal: Learn to use view sequences and indexes! I. View: A) create a view: Create ViewView nameAsSQL statement; Extended: When you need to change the column name-- Create view name (column name 1, column name 2,...

Rowid SQL statement explanation Select * from mytable2 s1 where rowid in (select rid from (select rownum r1, rid from (select rowid rid from mytable2) where rownum = 3 ); Select rowid rid from mytable2 indicates using rowid to identify mytable2

Simple Steps for installing Oracle 11g R2 (11.2.0) on RHEL5.5 1) required rpm for installation:# Rpm-UvhBinutils-2.17.50.0.6Compat-libstdc ++-33-3.2.3Elfutils-libelf-0.125Elfutils-libelf-devel-0.125Elfutils-libelf-devel-static-0.125Gcc-4.1.2Gcc-c ++-

It is mainly 2 points. First, createSequence;Then, when the insert statement is run, the position of the auto-increment field is writtenSequence name. nextval.The following describes how to create a table, then create a sequence, and write an insert

Technical aspects 1. Data Structure MongoDB uses document-based storage. Its data structure is similar to the BSON structure of JSON. Cassandra supports key-value storage, and each key-value stores a period of time, this time period actually plays

This is because em cannot find the corresponding font file when generating the button image. Solution: In the Oracle user environment 1. Apply the default font configuration file Cd $ ORACLE_HOME/jdk/jre/lib/ Cp font. properties. zh_CN.RedHat

You may encounter this situation. This week, we will analyze some data in the database of the previous week to obtain the corresponding analysis data. We can write a stored procedure in the database and call it every week. Record 1. A method that

Recently, Spring and Hibernate were used in the project for development. Thanks to Criteria, the query method design allows you to flexibly assemble query conditions according to the features of Criteria. Now we will summarize the usage of Hibernate

If developers use tables or views of other databases, they must create a View in the current database to perform cross-database operations. It is best not to directly use "databse. dbo. table_name ", because sp_depends cannot display the