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This article mainly introduces "how to solve the Oracle ORA-14148 problem". In the daily operation, I believe that many people have doubts about how to solve the Oracle ORA-14148 problem. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "how to solve the Oracle ORA-14148 problem"! Next, please follow the editor to study!

There is a hidden column on a table in Oracle12.1 's library that needs to be deleted. Hidden columns can be viewed through sys.dba_tab_cols.

Use the following command

Alter table A drop unused columns

Alter table A drop column "SYS_NC00027 $"

None of the above syntax can delete the column. There is no error in the first article, and the error in the second is as follows:

ORA-14148: DML and DDL operations are not directly allowed on the guard-column.

This hidden column is actually created because of a new feature of Oracle12c. Before 12c, when adding columns with default values to the table, if you do not want to affect production, you need default+not null, which only modifies the data dictionary, which is very fast, otherwise it will physically update every row, which is very slow and affect the production business. After 12c, columns with default values can be added quickly without not null, and the implementation technique behind this is achieved by adding hidden columns to the table.

This issue is an unpublished bug,Bug 18506065. The solution is as follows:

1. Install Patch 18506065

two。 Upgrade to Bug 18506065 fixed 12.2

3. Temporary workaround:

Alter system set "_ add_col_optim_enabled" = false

Implied parameter meaning:

SQL > select a.ksppinm name,b.ksppstvl value,a.ksppdesc description

2 from x$ksppi a dint Xeroksppcv b

3 where a.inst_id = USERENV ('Instance')

4 and b.inst_id = USERENV ('Instance')

5 and a.indx = b.indx

6 and upper (a.ksppinm) LIKE upper ('% add_col_optim_enabled%')

7 order by name

NAME

VALUE

DESCRIPTION

_ add_col_optim_enabled

TRUE

Allows new add column optimization

In addition, the data pump is exported with the parameter version=10.2, and this error may also be reported during import. You can also change _ add_col_optim_enabled to false first, and then modify it back after import.

At this point, the study on "how to solve the Oracle ORA-14148 problem" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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