Oracle

Oracle 21. Replace distinct with exists when submitting a search that contains a list of multiple tables (such as the Department table and the employee table), avoid using distinct in the SELECT clause. can generally consider using exist for

oracle| Data | database import Java.net.URL; import java.sql.*; public class Create { public Create () { } public static void Main (string[] args) { String url = "JDBC:ORACLE:THIN:@10.0.1.3:1521:SDCDB"; String query = "CREATE TABLE

It is believed that many children's shoes have had the painful experience of installing Oracle databases on Linux, most of which are problems with environmental settings. I recommend a foreign Daniel write Oracle installation script OTK, is written

The First/last function allows us to sort a dataset and process the first and last records of the result of the sort. After querying the first or last record, we need to apply an aggregate function to handle a particular column, in order to

When sorting, grouping, and indexing are done in an Oracle database, a lot of temporary data is generated. If you have a table of employee information, the database is the time to set up records to save. If a user queries by using the ORDER by sort

Second, SQL Structur Query Language Structured Query language is an object that operates in a relational database. DDL (data definition Language), for table or delete operations, and for modifying table constraints CREATE TABLE, ALTER TABLE,

In the previous article, it was mentioned that "if the corresponding block of data is changed between the time the transaction starts and the data block is read, then there may be something unexpected happening to us". Such unexpected results may be

In the day-to-day maintenance of Oracle, the following two situations are frequently required for our DBA kill session: 1. App complained that their application hang live, in the database query that their session by other sessions block, at this

First, bbed tools Installation of 1.BBED Oracle 11g missing bbed package, oracle11g bbed Install and example 1. Upload (SBBDPT.O ssbbded.o BBEDUS.MSB, the three files copy the linux64 version of Oracle) files $ORACLE

Oracle's official documents are large and often without focus, making Oracle novices look laborious. However, there are still many Oracle users who believe that any Oracle learning materials are not as authoritative and concise as Oracle's official

In practical work, often hear beginners say: "Large table partition can certainly improve query performance." In fact, when you do not understand the application of the situation, blind to create a partition not only can not improve query

When you start Tomcat, you are prompted to use 8080 ports, and then find the following findings: A 8080 port-occupied error occurs when you install Oracle with Tomcat, JBoss, and other 8080-port-consuming servers on a single machine First, check the

Use of dynamic SQL Oracle is actually better than SQL Server, but it's definitely not as strong as it is legendary. This is the feeling of Oracle in these days. It seems that a lot of things are so much better to listen to than to see the perfect.

Adding data records in asp.net+oracle and having automatic ID increments requires sequences and triggers to be set in Oracle, remember not to index, ASP. NET regardless of ID, as follows: 1, establish the sequence: CREATE SEQUENCE

The importance of data in a database is obvious to a management information system, and administrators are always trying to do everything they can to ensure their safety. In systems that require a 24-hour uninterrupted operation 7 days a week,

The role of audit1. Review of suspicious activities2. Monitor and collect data about the specified database activityTypes of audits1. Statement Auditing (STATEMENT auditing)2. Authority Audit (Privilege auditing)3. Objects auditing (object

The Oracle database provides several different ways to start and close the database, and this article will detail the differences between these startup and shutdown modes and their different capabilities. first, start and close Oracle databases

You need to know the fact that disk I/O is an important reason to affect Oracle database performance. In essence, any Oracle database is responsible for storing data, and querying data from disk is a very expensive and time-consuming operation.

Xinhua Tianjin, July 23 (reporter Zhang Jianxin) National Computer Virus Emergency Center reminder, Oracle released the July 2006 Emergency Patch Update bulletin, fixed multiple Oracle products in a number of vulnerabilities, I hope users download

The interconnection of different database platform is commonly called the heterogeneous service of the database, now each big database can realize such heterogeneous interconnection, but the specific implementation technology of each vendor is not