Summary of Small and Medium-sized ORACLE production tools, oracle practice

Summary of Small and Medium-sized ORACLE production tools, oracle practice

In daily production, data sources are often diverse. Let's talk about the amount of data in excel today, because many development languages now support exporting data to excel, however, some nonstandard practices may lead to the generation of unrecognized special characters? When special characters appear in the string, the actual audio is not great, but when special characters appear in the numeric field, this will affect the actual production. In this case, it will be very difficult to identify the special characters, because we cannot identify the specific characters, so we need to change our thinking, find out the standard data, and then use the universal data set out the standard data set. The rest is the data set that contains special characters. How can we find the standard data? It seems very difficult, it seems that there is a function that can solve the problem through regular expressions. Haha, it is really feasible and decisive. The specific usage method is as follows: select * from value_data p where p. line_num not in (select t. line_num from value_data t where REGEXP_LIKE (t. sale_num, '(^ [+-]? \ D {0 ,}\.? \ D {0 ,}$ )'))

In daily production, database sessions deadlocks may also occur due to improper design or operation. At this time, the database will wait, at this time, the competition between database sessions will seriously affect the actual business processing. Therefore, you must close the deadlock session quickly and accurately,

Select sess. sid,
Sess. serial #,
Lo. oracle_username,
Lo. OS _user_name,
Ao. object_name,
Lo. locked_mode
From v $ locked_object lo,
Dba_objects ao,
V $ session sess
Where ao. object_id = lo. object_id and lo. session_id = sess. sid;

Alter system kill session '46, 53 ';

With the above two operations, you can quickly and accurately close the deadlock session.

Database paging, which should be used by everyone. Record it. select * from (select rownum no, t. line_num, t. ven_cust from value_data t) where no> 1 and no <11