Oracle

The company I serve not only has an Oracle database, but also has a SQL Server database, so I often meet people asking me two questions. The first type is usually "can you teach me to use Oracle?" In the beginning, my polite answer to this is

If you use the Oracle default creation method when you create a foreign key constraint, it cannot be deleted when the referenced data is deleted, which gives us more flexibility in oracle9i, but we use on DELETE cascade and on delete set Null

Do a C # and Oracle system, think of each client also install Oracle client is really troublesome, so the Internet search, whether there is no way to install the client, is really good, Oracle has already thought of this problem. On his website has

SQL is the language used to access Oracle databases, and Pl/sql expands and strengthens the functionality of SQL, while introducing stronger program logic. Pl/sql supports DML commands and SQL transaction control statements. DDL is not supported in

We have recently taken into account the fact that our database-side write stored procedures are used in temporary tables, as we are not yet clear on what the database end is dealing with? Is the same way as SQL Server, there are some problems, and

The main purpose of the blockade mechanism is to control the concurrent operation, to block the jamming and to ensure the consistency and accuracy of the data. There are three ways to block Oracle database: Shared blockade, exclusive lockdown,

The problem extended from a customer's real optimization case. A customer's database needs to be optimized, but because the program developer is not involved, this optimization cannot be modified for SQL. Database-level adjustments generally have

Because the B*tree index does not store null values, some Oracle queries do not use indexes when the indexed field is allowed to be empty. Most of the time, it appears that we can use a full index scan, which may give Oracle the chance to discard

From the database to guide a data when there is a very strange problem, Chinese garbled. First of all, it can be confirmed that the data in the database is in Chinese, there is the use of toad to connect the query is also Chinese. But after the

Oracle execution plans are not unfamiliar to us, and often we only look at the performance bottlenecks in our work and have no idea how the execution plan is generated. The following examples are used to simulate the evolution of data access and

The Oracle 10g version is designed to redesign the operational functions of data entry and output to increase the ability to disconnect and connect in the input or output work. Minor changes to these features can facilitate the operation of the DBA

Today, I learned about the latest popular Ruby on Rails, which is that when a code generator links an Oracle database, it checks for half a day of data. Finally found a way, ^______^. 1. Installation drive http://rubyforge.org/projects/ruby-oci8/

BeginSys.dbms_job.submit (Job =>: Job,What => ' Check_err; ',Next_date => trunc (sysdate) +23/24,Interval => ' trunc (Next_day (sysdate, ' ' Friday ')) +23/24 ');CommitEnd Where: Job is the system automatically generated number, Check_err is my

Configuration of the RMAN catalog database 1, the function of catalog database 1 centralizes the Rman database (the backed-up metadata) and can be synchronized with the target database Controlfile 2 The backup script that holds the Rman 2, the

Looking at the optimized document, it is found that the hint of the specified index can also be column-style. In 9i and previous versions, the index hint format is/*+ index (table_alias) * * * or/*+ index (table_alias index_name) * *, but in 10g it

1. Cross-efficacy Rman backup In the case where the Rman catalog and the physical backup destination are not synchronized, we can use the Crosscheck command to verify that the Rman information in the control file or recovery directory is the same

Attempts to logically recover OCR devices have led to problems with inconsistent OCR status. Perform the following actions on one of the nodes of the RAC: bash-2.03#/data/oracle/product/10.2/crs/bin/ocrconfig-export/export/home/oracle/ocr.log

The previous article describes how to migrate AWR data, which describes how to delete snapshot data that you no longer need. For the current database-generated snapshot, no manual processing is required, and Oracle automatically deletes expired

Eight Copy Introduction to 8.1 image replicas RMAN can create database data files, archive redo logs, or exact copies of control files. The Rman copy is a copy of these files, and the difference is only in the name and location changes. We don't

1, logical backup and physical backup differences 1 Physical Backup: Backup data files and control files, backup the physical structure of the entire library, mainly for media recover 2 logical backup: Back up the data structure and data of the