Database Administrator

Database Version: Oracle 10.2.0.5-64Number of nodes: 2Operating system version: CentOS 5.6-64Awr report today finds gc buffer busy wait timeGc buffer busyThis wait event, also known as global cache buffer busy prior to Oracle 10g, specifies the time

If the current system time of Oracle is inserted, SYSDATE can be used. Insert into floor values (SYSDATE );Insert Date data to Oracle Database (to_date usage) Today, I encountered the need to insert date data into the Oracle database. I want to

Database dirty reads, non-repeated reads, and Phantom reads are all related to the isolation of transactions. First, let's take a look at the four features of transactions.Four major features of transactions (ACID ): Atomicity: a transaction is

Today, an Oracle 11.2.0.3 environment is installed. It is found that diskmon is always in the offline status: [Root @ osdbso ~] # Crs_stat-tName Type Target State Host------------------------------------------------------------Ora. DATA. dg ora...

Before the server process obtains the redo allocation latch for redo log buffer allocation, You need to sniff the redo log file to check whether there is sufficient space. If the space is insufficient, the sp will send a request for the switch log

After sybase 12.5.4 is installed on RedHat as 4 and Initialization is complete, run isql-Usa-P to report the error: The context allocation routine failed when it tried to load localization files !!One or more following problems may caused the

When you delete a record in the mysql database today, the following error message is displayed: Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that Uses a KEY column To disable safe mode, toggle

Oracle uses a variable-length storage method to store number data. Each number value is stored in the database in the form of scientific Notation: one byte is used to store the symbol/index, and up to 20 bytes are used to store the ending number.

I did not know much about the remote restoration of the RMAN backup database. When I went to Shangguan technology to attend lectures last Saturday, teacher Zhang lie is talking about RMAN backup, so he has recovered a lot of memories and understood

1. Overview New Features of Oracle 10g InMemory Undo: From the previous introduction, we can know that the Undo management method is the same as the conventional data management method. when data is modified, a pre-created image is created in the

V $ session parameters SADDR: session addressSID: session identifier, which is often used to connect other columns.SERIAL #: sid will be reused, but when the same sid is reused, serial # will increase and will not be repeated.AUDSID: audit session

1. Download PL/SQL Dev 2. Download the simplified Oracle client 3. Install PL/SQL Dev and the Chinese package 4. decompress the Oracle thin client. For example, extract the Directory D: \ oracle10g. 5. Configure the Oracle connection. D: \

I. IO sched is a method used by the operating system to determine the order of IO operations submitted on Block devices. There are two purposes: Improving IO throughput and reducing IO response time. However, IO throughput and IO response time are

EnvironmentOn servers 192.168.1.89 and 90, the operating system is linux Red Hat as 5.2, Oracle 10.2.0.4 is installed, and a single instance database webdb is created respectively.Configure the Data Guard environment with the webdb Of the 89

In applications with large data volumes, you often need to optimize database configurations and SQL statements to ensure the concurrency of applications when loading large data volumes. MySQL has a built-in analyzer Profiler. With Profiler,

Recently, sysbench has been used for many performance tests. It also summarizes its features and usage and precautions. Sysbench is a multi-thread performance testing tool that can perform performance tests such as CPU, memory, IO, and database.

Postgres Plus Advanced Server has two migration tools, one graphical interface and one command line interface. The following uses a graphical interface as an example. Read more: Install ipvs Plus Advanced Server 9.2 on 64-bit RHEL6.2 1 First, you

When tablespace in the database is deleted today, it is found that it cannot be deleted, the error message is: "ora-00604, ora-02429: Unable to delete the index used to force a unique/primary key. " In the end, it is found that another user did not

The DECODE function is one of the powerful functions of Oracle PL/SQL. Currently, only oracle SQL provides this function, and other database vendors do not yet implement this function. What is the purpose of DECODE? First, let's construct an example.

Mongodb databases are also inseparable from necessary maintenance, such as backup, recovery, import, and export. In fact, backup and recovery are easier to import and export than normal, so most of the time you can use backup and recovery