oracle case statement

Oracle SQL optimization Case 1: oraclesql Optimization An Alert email is sent from a job in the monitoring alarm log file (Alert). The tablespace TEMPSCM2 cannot expand the temporary segment, indicating that the temporary tablespace has been used up and the TEMPSCM2 tablespace is not enough. Dear All:The Instance SCM2 'alert log occured the ora errors, please see the detail blow and take action for it. Too

Continue to look at the second case of the query, including the table connection: SQL> Create Table T as select * From dba_users; The table has been created. SQL> Create Table T1 as select * From dba_source; The table has been created. SQL> ALTER TABLE t add constraint pk_t primary key (username ); The table has been changed. SQL> ALTER TABLE T1 add constraint fk_t1_owner foreign key (owner)2 references T (username ); The table has bee

)The results and execution time of the preceding four sqls are the same after ORACLE analysis, but the principle of shared memory SGA from ORACLE is as follows,It can be concluded that ORACLE will analyze each SQL statement and occupy the shared memory,If the SQL string and format are completely the same,

Oracle case when usage 1. the case when expression has two forms: Simple Case function CASE sex WHEN '1' then' male 'when' 2' then' female 'else' others' END -- Case search function CASEWHEN sex = '1' then' male 'when sex = '2' th

In Oracle databases, consistent gets is useful for judging the performance of a section of SQL, and generally comparing the performance of two segments of SQL is not to see whose execution time is short, but to see whose consistent gets small. But this is not absolute, the following example is a counter example. One: Normally, data that is not in logical RAM buffer is read through physical reads, and physical reads usually follows a consistent gets.

Oracle Active Data Guard adjustment case [2] The customer's Oracle 11gR2 Active Data Guard environment, the master database's standby_file_management = AUTO, the Standby database's standby_file_management = MANUAL, resulting in the Data file operations added to the tablespace in the master database not synchronized to the standby database, no file similar to UNNA

Oracle Database cursor case description and source code 1. cursor ConceptCursor is a data buffer provided by the system for users to store the execution results of SQL statements. Each cursor area has a name. You can use SQL statements to obtain records from the cursor one by one and assign them to the primary variables for further processing. In databases, cursor is a very important concept. A cursor provi

Differences between Oracle-Decode () and case statements: Example: 1. Case statement: Select case sign (5-5) When 1 then 'is positive' When-1 then 'is negative' Else 'is 0' end From dual; Background implementation: If (sign (5-5) = 1 ){ Is positive '; }

* from(Select a. *, rownum RnFrom (select * From table_name)Where rownum )Where rn> = 21 Select * From table_name indicates the original query statement that does not flip pages. Rownum The paging query statement given above has a high efficiency in most cases. The purpose of paging is to control the size of the output result set and return the result as soon as possible. In the preceding paging query

This is a real oracleORA-19815 solution) case, hope to help everyone.Today, the platform of a friend company encountered slow login and slow data query, and the failure to log on to oracle monitored through spotlight. No problems were found by checking the system memory and processes, finally, I found myself. I first checked the memory and processes of the platform, and did not find any problems. Finally, I

The ORACLE tutorial is Oracle PL/SQL getting started. I have already learned the basics of PL/SQL programming. This article will use a case study to deepen my understanding of these knowledge points. I. Case Study A database has two tables about employee information, salary, and department information of a company. Th

In the oracle query statement, the use case when statement Syntax of case when is as follows: case when expression then valueA else valueB end; the specific use is as follows: select (case