Oracle

Another example of "12c more consumption than 10g index back-table" case, colleagues in 12c run the buffer get is very high, but in 10g run a low buffer. Doubt whether the 12c optimizer has a problem. This 10g environment and 12c environment, the

Cursors are divided into implicit cursors and display cursors. One, implicit cursorsThere is an implicit cursor attached to the SELECT * into and DML operations (update, delete, insert). Attributes of an implicit cursor Sql%rowcount integer

Oracle database installed on the Ali Cloud, one day received the following alerts:Name=atabasenameType=database InstanceHost=izw2519p6r9uzeeeMetric=statusTimestamp=nov, 2014 4:16:37 AM CSTSeverity=criticalmessage=failed to connect to database

In some cases, may be due to misoperation, not small first drop diskgroup, this time do not be nervous, such a failure, can be a perfect recovery through kfed (data 0 lost). If the related ASM disk is further damaged, then the subsequent recovery is

Modify Oracle Instance name System Environment: CentOS 6.5Oracle Version: 10.2 1, check the original database instance name$ echo $ORACLE _sidOrcl $ sqlplus/as SYSDBA> select instance from V$thread;INSTANCE-------------------------------------------

Has Netizen consults the database to start the report ora-01092:oracle instance terminates. Force disconnect, request help handlingDatabase version Trace file D:\app\administrator\diag\rdbms\orcl\orcl\trace\orcl_ora_5648.trcOracle Database 11g

Sequence meaningThe Oracle database provides a sequence object, provided by the system with its own growing serial number, usually used for the growth of the primary key or ordinal number of the database data records; Nanjing OCM Training Create a

Failure phenomenon:How do I make a cold backup of an Oracle database in case of an emergency, without opening the Oracle log archive?Solution: A cold backup of the Oracle database, sorted as follows: When do I have to use cold backup? 1. Database

VARCHAR2 (* char) and VARCHAR2 (*) A Hibernate automatic table was recently used, and when a string is used, the VARCHAR2 type field is created by default, such as setting length=10, after which the field property is Varchar2 (. Char), not VARCHAR2

There are three types of lob: Blob:binary Large Object Binary Large ObjectsClob:character Large Object single character large objectsDouble-byte Character Large Object Double Byte character large objectsLarge data types in Oracle:Long:

Advantages of using partitions: 1. Enhance usability: If a partition of a table fails, the data in other partitions is still available; 2, Maintenance Convenience: If the table of a section of the fault, need to repair the data, only repair the

Oracle An RDBMS is used in practice for various types of related locking mechanisms, andOracle latch is one of the most frequently used, and the following articles are mainly about the concept of latch (latch) and understanding the implementation of

A Set the appropriate SGA People often complain that server hardware is good, but Oracle is slow. It is likely that the memory allocation is unreasonable. (1) Assuming that the memory has 512M, this is usually a small application. Oracle's SGA is

Overview Wait events can be divided into two main categories, namely, Idle (IDLE) Wait events and non idle (non-idle) wait events. 1). Idle Wait Event Oracle is waiting for some kind of work, not paying too much attention to this part of the

Recently a friend accidentally caused a very big accident, I almost took a lawsuit. In doing database migration, remote misoperation deletes the original database of several databases, such as system initial installation, and the disk space usage is

If we give each user permission directly, it would be a huge and cumbersome task, and it would be inconvenient for DBAs to manage it. By adopting a role that enables: Privilege Management is more convenient. Assign roles to multiple users,

Installing oracle in linux is a daunting task. Its complexity far exceeds that of installing the linux operating system. If oracle is successfully installed, some linux technologies are also mastered. This article describes how to install oracle 10

Assm level-3 bitmap is the basic skill knowledge of dba. Here we use the test method to verify the principle of level-3 bitmap.1. Create tables required for the lab environmentSQL> create tablespace a1 datafile

In RAC of 12c, because it is a flex cluster, the instance runs randomly. For example, instance 3 runs on Node 2 and instance 2 runs on Node 3. This is also true after restart.We can handle this in this way, so that the original running instance is