Database Administrator

When creating tablespaces and files, whether the directory exists and whether the space is satisfied is a concern. To ensure the consistency of system data storage policies and avoid large rework actions, this process must be considered. In many

I found that Oracle's service and listener services started normally today, but the sqlplus logon prompt is as follows: ERROR: A ORA-01034: ORACLE not available ORA-27101: shared memory realm does notexist Most of the solutions to this problem

The volume installation package specified by Oracle 11gR2 is 10.2, but it is not actually usable. It downloads the 11.1 package, but it still encounters several errors and is modified back and forth ...... If the installation fails and you need to

Write down the basic implementation principle of group by in MySQL. Because group by actually performs sorting operations, and compared with order by, group by mainly only performs grouping operations after sorting. Of course, if other Aggregate

Class op_log (models. Model ): Op_date = models. DateTimeField (auto_now = True) Op_log = models. CharField (max_length = 2000) Class op_log1 (models. Model ): Op_date = models. DateTimeField (auto_now_add = True) Op_log = models. CharField

When logging on to the Oracle Management Server according to the document, the first login is successful. If you log on again after shutdown, the following error may occur: domain name resolution error or login denied error. The error is because the

Symptom: Oracle GridInfrastructure 11gR2 is installed on a single instance database for creating ASM for the standby database. However, the Create asm gui is displayed after you log on to the grid user to execute the ASMCA command, an error occurs

The syntax for querying the total number of records in a table is select count (*) FROM TABLE_NAME. This may be the most frequently used type of SQL statements. This article discusses how to obtain the maximum number of records. This article is

Why should we discuss this issue? It is rooted in history. Let's start with Oracle 10 Gb. Before 11G, if you want to add a new column to a large table and the new column has a default value, if you want to use alter table xx add xx_1 number default 1

Preface In addition to installing the Oracle database software, we often need to install the Oracle client on a host without an Oracle database environment to access the Oracle server over the network. The steps for installing the Oracle Instant

-- Test environment:OS: RedHat linux (64)Primary:IP: 192.168.94.198SID: dgdb1Hostname: dg1DB_UNIQUE_NAME: dgdb1Database: 10.2.0.1 (64)Standby:IP: 192.168.94.199SID: dgdb1Hostname: dg2DB_UNIQUE_NAME: dgdb1_sDatabase: 10.2.0.1 (64)  -- Preparations

Operating System: 64-bit Linux RedHat 6.3 Environment preparations for installing Oracle 12C 1. Install the dependency package Binutils-2.20.51.0.2-5.11.el6 (x86_64)Compat-libcap1-1.10-1 (x86_64)Compat-libstdc ++-33-3.2.3-69.el6

Master Database: vsgpdbStandby Database: dgdb  1. confirm that the master database is in archive ModeSQL> archive log listDatabase log mode Archive ModeAutomatic archival EnabledArchive destination/gp/archOldest online log sequence 1307Next log

Each Oracle version has many new features and technologies. These technical features can greatly improve Oracle operation efficiency and application performance, or improve our daily work capabilities. Temp tablespace is a special tablespace object

After entering the CBO optimization pipeline, the cost calculation value determines the selection of execution plans. An execution plan with good performance is based on the "appropriate" statistics as much as possible. CBO has gone through two

Oracle Vault is a complete O & M Security System Framework launched by Oracle. Vault is a good option among many O & M organizations. The principle of Oracle Vault is the split protection of security responsibilities. From the assumption that the

Oracle Database is developing to this day, and I/O is king. One of the important features of the ExtraData all-in-one machine is to maximize the I/O capability and increase the I/O throughput. Compared with CPU and memory, IO Storage has its own

1. Basic hardware requirements for installing Oracle databases 1.1 Basic Requirements for memory At least 1 GB of physical memory Oracle officially recommends 2 GB memory or more Here, we can meet the basic conditions in the experiment environment.

Full recovery: only the corrupted data file is restored, and the file is restored independently. The log Sequence starting from the backup to the current log sequence cannot be reduced. Passive Incomplete recovery: one or more log sequences

Generally, DBA and SA must maintain a correspondence between the OS disk and the disk in the Oracle database ASM Group when managing the disk.If SA is uncertain or DBA cannot be found, use the following method to find the corresponding relationship.