Oracle

Autotrace is an sql*plus feature that automatically tracks the generation of an execution plan for SQL statements and provides statistics about the processing of the statement. Sql*plus Autotrace can be used instead of SQL Trace, the benefit of

Basic conceptsNested Loop join:Each row in the Outer table joins the corresponding record in the inner table, similar to a nested loop.Sort Merge Join:Sort the two tables before you join.Hash join:The smaller of the two tables constructs a hash

The actual operating environment is: use Jython to link the Oracle database in Eclipse+pydev. The method has two, as shown below. (Note: the. jar file path that will be used is added to the system variable Classpath)One:Note: Use the Ojdbc.jar

16, all the way after installation, will prompt the following interface, you need to log in the following directory with root, and then execute the two scripts.At this point, the installation of Oracle software is complete, and the database can then

After a long time learning Oracle, so share with you, after reading this article you certainly have a lot of harvest, hope this article can teach you more things. Each step of the Oracle execution plan returns a set of rows that are either used for

First, the problem leads① Suppose that when an online user buys a book, there is an order with an order number of 001 in the database, where a status field is ' valid ', indicating that the order is valid;② Admin to check this 001 order, and see the

Create a tablespace Create tablespace ICITY datafile 'd: \ Oracle \ oradata \ orcl \ ICITY. dbf' size 400 M autoextend on next 10 M maxsize unlimited extent management local; Create temporary tablespace Create temporary tablespace ICITY_TEMP

2 tablespace The maximum logical layer in Oracle disk management is the tablespace. The four tablespaces that must be created in Oracle11g are SYSTEM, SYSAUX, TEMP, and UNDOTBS1. 2 SYSTEM: stores data dictionaries, pl/SQL code, etc. 2 SYSAUX: stores

8.3.2 Dropping Tablespaces and Deleting Datafiles8.3.2 Delete Tablespaces and data files When you delete one or more datafiles or drop one or more tablespaces in the primary database, you also need to delete the corresponding datafiles to the

1.1. ORA-16664, ORA-16625, TNS-12537 Master database: 16664,000 0, "unable to receive theresult from a database" // * Cause: During execution of a command, a databasein the Data Guard // Broker configuration failed to return a result. // * Action:

Today is. Learn the basic acfs knowledge. Oracle acfs introduction:Oracle Automatic Storage Management Cluster File System (Oracle ACFS) is a multi-platform, scalable file system, and storage management technology that extends Oracle Automatic

--- Indicates flashing back to the database --- Use a flashback table to restore the table content to a specific time point in the past --- Restore from the deleted table --- Use the flashback query to view the database content at any point in time -

If someone uses it: Select t. * from table name t where field = xxx for update Instead: Select t. rowid, t. * from table name t where field = xxx for update This is the case when you update data. For update does not contain rowid. It is a silly

Today, I encountered a strange problem at oracle10g. One SQL statement was very fast on database 1 and very slow on Database 2. Database 2's data was imported from database 1 and the data volume was similar. Run 0.01 s on database 1. SQL> SELECT .*,2

Manually back up archived logs 1. database01 [Oraprod @ db01 scripts] $ pwd/Usr/tivoli/scripts[Oraprod @ db01 scripts] $ ls1. txt nohup. out oraicr0.sh scheoraicr0.shBKlog null oraicr1.sh scheoraicr0.sh. testBKlog.tar oraarch. sh oraicr1.sh. orig

1. If it is just deleted, there are two methods: Run the show parameter undo command to view the current database parameter undo_retention settings. Shown as follows:Copy codeThe Code is as follows:Undo_management string AUTO Undo_retention integer 1

Before 11g, You need to manually maintain the partition. After 11 GB, interval is used to implement automatic expansion of partitions, which simplifies maintenance. By YEAR: INTERVAL (NUMTOYMINTERVAL (1, 'Year '))By MONTH: INTERVAL (NUMTOYMINTERVAL (

When calling the dynamic performance view related to Oracle in a process, package, function, or trigger, you must grant appropriate permissions. Otherwise, you will receive an error message indicating that the table and view do not exist. Even if

At work this morning, the customer called and said that the system could not be accessed. the user name and user number could not be loaded! When I heard this problem, I first thought about whether the server was restarted. Why was Oracle database

The Function Room of the Database Control Language controls the user's access permissions to the database. The DBA determines the operation permissions of a user on a certain type of data. Oracle GRANT permissions using the GRANT statement and