Oracle

How to obtain the values of 6th to 10th records in a table. The first method is to use the minus statement: Assume that the DDL statement is as follows: Create Table T (ID varchar2 (4) primary key, value INT) The first method is to extract

UNIX timestamp is the number of seconds since '2017-01-01 00:00:00 'GMT, expressed as an integer. The time in Oracle is date type. The following functions provide two Oracle functions for time conversion. (1) converting from UNIX timestamps to

This problem is often encountered during the use of Oracle, so I also summarized some solutions :) 1) Find the deadlock process: Sqlplus "/As sysdba" Select S. username, L. object_id, L. session_id, S. serial #, L. oracle_username, L. OS

(1) Check the running status, log files, backup status, space usage of the database, and usage of system resources of the Oracle database every day to discover and solve the problem. (2) Monitor the space expansion and data growth of database

The dbms_metadata.get_ddl package obtains the DDL script of the database object. As follows (executed in sqlplus ):1. Get the DDL statement of a table:Set serveroutput onSet linesize 1000Set feedback offSet long 999999 ------ incomplete displaySet

1. RAC (or OPS in Oracle 8i) RAC is a myth that has been widely used for a long time. Because RAC has high hardware requirements, especially before 9i, it was almost always running on minicomputers, many people think of RAC as a synonym for

In many cases, when the application administrator notifies us that the application is slow and the database is slow, when we go to the database, we do a few examples of select and find the same problem, sometimes we will not be able to start,

Read this article How 32bit Oracle expands SGA> In my tests, because I have lowered the SGA starting point (there is no substantial relationship between reducing the SGA starting point and this Article, just because my test database has been lowered

1.2.2. query Partition Table records: SQL> select * From dinya_test partition (part_01 ); Transaction_id item_id item_description transaction_date -------------------------------------------------------------------------------- 1 12 books 2005-1-14 1

Truncate and delete have the following differences:1. truncate is very fast on various tables, whether large or small. If the rollback command Delete is used, the truncate command is not used.2. truncate is a DDL language. Like all other DDL

---- 1. Having clause usage ---- The having clause controls the row group determined by the group by clause. Only constants, clustering functions, or columns in the group by clause are allowed in the having clause. ---- 2. External join "+" Usage ---

1. Waiting for monitoring casesSelect event, sum (decode (wait_time, 0, 0, 1) "Prev ",Sum (decode (wait_time, 0, 0) "curr", count (*) "tot"From v $ session_waitGroup by event order by 4;2. rollback segment contentionSelect name, waits, gets,

[1] CRS (cluster ready services) is a new feature of 10grac. It is different from database and can be downloaded free of charge on OTN.[2] before installing 10g RAC, you must first install 10g CRS[3] CRS can run on other cluster software, such as

Recently, I just made a performance optimization job. According to the statspack report of one week, I wrote an optimization solution. I. Existing major performance problems of the systemAccording to the typical statspack report in the last week,

The most important component of Oracle SQL running time is the time spent preparing new SQL statements for execution. However, if you understand the Inherent Mechanism of executable plan generation, you can control the time spent by Oracle in

When Oracle DBA is used, the application administrator notifies us that the application is slow and the database is slow, when we go to the database, we do a few examples of select and find the same problem, sometimes we will not be able to start,

Integrity constraints are used to enhance data integrity. Oracle provides five integrity constraints: CheckNot nullUniquePrimaryForeign key Integrity constraints are a rule that does not occupy any database space. Integrity constraints exist in data

 1. What is an execution plan? An explain Plan is a representation of the access path that is taken when a query is executed within Oracle. Ii. How to access data At the physical level Oracle reads blocks of data. the smallest amount of data read is

Oracle Database Administrator responsibilities The Oracle Database Administrator should perform regular monitoring on the Oracle database system as follows:(1) Check the running status, log files, backups, database space usage, and system

  I always wanted to provide an interface on/off audit at the application system layer. That is to say, you can enable or disable the database audit function at the application system level. However, after several days of trying to enable or disable