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Blocking is a common situation for DBAs. especially poor application design blocking can cause serious performance degradation until the database crashes. For DBA, it is necessary to know how to locate Blocking is a common situation for DBAs.

Some time ago, it was found that the operating system time of a newly loaded Rac database was incorrect. When dbtimezone was queried, it was found to be-, indicating that the time zone was incorrect; Some time ago, it was found that the operating

Oracle uses the results of one query to update the data of another table. The simulation experiment is as follows. Use the query results of table t2 to update data with the same id as table t1. Oracle uses the results of one query to update the data

When upgrading the Oracle database from 11.2.0.1.0 to 11.2.0.2.8, the software upgrade is normal, the instance upgrade is normal, and the psu is upgraded. Run @? Rdbmsadminc When upgrading the Oracle database from 11.2.0.1.0 to 11.2.0.2.8, the

Give normal users the query permission on the v $ view, results in a ORA-02030 error, ORA-02030: queries only from a fixed table view (ORA-02030: canonlyselectf Give normal users the query permission on the v $ view, results in ORA-02030 errors, ORA-

Decode can only be equivalent, while casewhen can be used for range and condition differentiation. decode can do the same as casewhen. In terms of efficiency, I personally think Decode can only be equivalent. case when can be used for range, range

Before innodb_memcache is installed, You need to import the configuration SQL. The configuration SQL is located in the share directory of the installation directory, and the file name is innodb_memcached_config. SQL, which is imported Before

By default, OracleDatabase11g has a system-defined MovingWindowBaseline, which corresponds to all AWR data during the AWR retention period. Oracle Database 11g has a system-defined Moving Window Baseline by default. This Baseline corresponds to all

Oracle has multiple ways to obtain a query plan for an SQL statement, such as using the explain Plan command and pressing the F5 shortcut in PLSQLDeveloper, but it is used for SQL optimization, Oracle has multiple ways to obtain a query plan for an

When creating an Oracle index, we add parallel indexes to build the index quickly. After adding parallel indexes, this column will be in parallel. When accessing an index with a degree of parallelism, CBO may consider When creating an Oracle index,

Today, we used to import all the information of one Oracle user to another. For example, if one user on one machine is aa, we need to use aa on another machine. Today, we used to import all the information of one Oracle user to another. For example,

The following content contains the single-instance installation manual for installing Oracle11GR2 on the IBMAIX6.1 system. This book covers the Silent Installation of oracle database software and OUI (Common Graphics The following section contains

This article mainly records the complete process of creating a physical standby database for reference in practice. This experiment is designed to create two databases, TEST, STD_ASSG, and TEST, on the local machine. This article mainly records the

As a toolkit launched earlier in Oracle, Statspack was first introduced in Oracle8 and has been widely used in 9i. From the development process, Statspack laid the foundation for the existing AWR As a toolkit launched earlier in Oracle, Statspack

Cursor sharing Cursor is a key and difficulty in Oracle learning. Oracle's Cursor is based on the optimization of SQL parsing Parse consumption. Based on different memory caches Cursor sharing Cursor is a key and difficulty in Oracle learning.

As the most mature commercial database, Oracle database provides many security O & M tool solutions for a large number of user groups while stabilizing its core functions. Number As the most mature commercial database, Oracle database provides many

Databases have many processing models for hierarchies. You can design models based on your needs. Of course, the simplest and easiest model to design is the so-called adjacent model. In this regard, other databases such as Oracle Databases have many

Heaptable storage: The most common and commonly used method in Oracle Database Systems is heaptable. The data storage method of the heap table is unordered, that is, any D Heap table Storage: The most common and commonly used heap table in Oracle

MongoDB stores images and other files in two ways (this article is intended for users who can already use MONGODB to integrate Spring) MongoDB stores images and other files in two ways (this article is intended for users who can already use MONGODB

Check whether the user has the Flashback permission select * fromsession_privswhereprivilegelike Check whether the user has the Flashback permission select * from session_privs where privilege like Check whether the user has the Flashback