Changing all the semantic VARCHAR2 length in BYTE to CHAR columns

Hello

our database is to use character set AL32UTF8, i.e. multibyte.

All our VARCHAR2 columns have been specified as VARCHAR (xxx) semantic unspecified length explicit, which makes VARCHAR(xxx BYTE) because NLS_LENGTH_SEMANTICS is set on 'BYTE' (default Oracle).

I wonder now if it would cause problems to enter and execute the ALTER TABLE statement to change all the columns of VARCHAR2(xxx BYTE) to VARCHAR2(xxx CHAR), leaving the same xxx. For example, if a VARCHAR2 column (100 BYTE) would be amended to be VARCHAR2(100 CHAR).

If I am not entirely mistaken, - on the contrary - it would make the columns longer, not shorter; I expect to not get errors on the values of existing records being too long to change the specifications of the column in this way (as it may happen when the shortening of a VARCHAR column, for example, of varchar (10) to varchar (5)). So I think the ALTER TABLE statements should go without problem.

I would also change NLS_LENGTH_SEMANTICS to TANK.

Are there problems or consequences I might meet when I do this? I'm not worried about the implications for code enforcement external or such, but simply the integrity / performance / etc on the database level.

It is a 11.2.0.x of Oracle database.

Thank you

MSA

You can make this change to your drawings, but not for Oracle schemas or third party. It would usually not be supported.

You will not get the errors associated with the data in the table. However, you can encounter errors due to:

1 index of issues of key length - the maximum length of an index key in bytes (based on the column definitions, no real content column) is limited to about 70% of the size of the block of the tablespace containing the index. If you try to do a column belonging to a larger index key by applying the semantics of length in characters, you get an error if the change causes the index key limit.

2. some columns cannot be changed. This includes, but may not be limited to, the columns that are referenced by expressions of virtual column and the functional index expressions, columns that have indexes defined on them, and columns field belonging to a partitioning key.

3. you can not change the columns that store attributes of the type defined by the user in this way. You must change the definition of type instead.

Also, do not change NLS_LENGTH_SEMANTICS initialization file. Include the keyword CHAR in your scripts or ALTER SESSION SET NLS_LENGTH_SEMANTICS = CHAR in these scripts. Value of the initialization file will affect all the scripts for Oracle products and third-party and can create tables with the semantics of unexpected length. Therefore, for compatibility reasons, this parameter in init.ora/spfile parameters is not recommended.

Thank you

Sergiusz

Post edited by: Sergiusz Wolicki (Oracle)

Tags: Database

Similar Questions

  • change all the user session

    Hello..

    I wanted to change constantly throughout the user session, so that all users the date and time in "' DD/MM/YYYY HH24:MI:SS
    so I did the following AS SYSDBA

    ALTER session set nls_date_format = "DD/MM/YYYY HH24:MI:SS";

    but whn the other user
    Select sysdate double

    they still get the date in the format "DD/MM/YYYY '...
    their session was' altered nt...

    any idea to make it permanent for the whole session...

    Hello
    You can change all the time as follows:

    Step 1: Change your pfile (settings file) file by adding the line:

    NLS_DATE_FORMAT = "DD/MM/YYYY HH24:MI:SS.

    Step 2: Bounce your database (close and restart).

    SQL > shutdown immediate
    The database is closed.
    The database is dismounted.
    ORACLE instance stops.
    SQL > startup
    ORACLE instance started.

    Total System Global Area 289406976 bytes
    Bytes of size 1248600 fixed
    117441192 variable size bytes
    167772160 of database buffers bytes
    Redo buffers 2945024 bytes
    Mounted database.
    Open database.
    SQL > alter session set nls_date_format = "DD/MM/YYYY HH24:MI:SS";

    Modified session.

    SQL > select sysdate to double;

    SYSDATE
    -------------------
    22/02/2011-16:08:23

    It will be useful.

    Best regards

    Rafi.
    http://rafioracledba.blogspot.com/

  • To work with the text to the assignment by the cursor of the large fragment of page it is necessary to change all the time down, 'against the judgment", but the page automatically does not start to rise upward, as happens in other browsers. I ask you for

    After the transition to Windows 7, there was a problem with Firefox. To work with the text to the award by the cursor of the large fragment of page it is necessary to change all the time down, 'against the judgment", but the page automatically does not ascend to the top as it was earlier, and like that occurs in other browsers. It is necessary to press the other key "down" which is him very troublesome. Resettlement on an earlier version (8.0) earlier irreproachably working, gave nothing. I ask you to help

    You must activate the module bar (Firefox > Options or view > toolbars;) CTRL + /) or find bar to make Firefox scroll the page while selecting the text (Ctrl + F).

  • I can not open a new tab (empty) I change all the settings. However as I said well can I open a new tab with a link without a link, I can't open a new (empty) tab.

    I can not open a new tab (empty) I change all the settings. However as I said well can I open a new tab with a link without a link, I can't open a new (empty) tab.

    Uninstall the toolbar Ask and it should work again. There is a compatibility issue with the Ask and Firefox toolbar that prevents the opening of new tabs.

    There are a few places to check for the Ask toolbar:

  • My background changes all the time. How can I get it stays the same?

    The background on my laptop changes all the time. I am constantly going to the control panel and change = ing it and invited her to "Save Changes". This never happens. Can someone tell me why this is happening?

    Hi karey204.

    Office operating system preferences and settings, such as the desktop wallpaper, sounds, themes and screensavers can not be saved if the user account is damaged. Create a new user account to solve the problem.

    Note: If my post answered your question, please mark it as an "accepted Solution".

  • All my programs have gone there program default open in Word 2007 how to change all the programs back to defuault there?

    All my programs are passed to the default opening program here as Word 2007 How do I change all the acknowledgement of programs to defuault there? I uninstalled the steps and it made no difference so I reinstalled and opened. Then he did the same as before. How can I get my programs back to default here?
    This problem started as soon as I updated my Windows 7 - 32 bit - please help. :(

    Hello mattyboy1212,

    Thanks for posting on the Microsoft answers Forum.

    Try these steps and see if you can associate the default programs. If they are associated with Word, and then change them to the correct program.

    1. click Start and then click Control Panel.

    2. click on programs link.

    Note: If you see small icons or large icons in the control panel display, you will not see this link. Click on the default programs icon, and then click the link associated with a file type or Protocol with a program . Go to step 4.

    3. click on the link to Open a file in a specific program type always under default programs .

    4. in the set Associations window, scroll down until you see the file extension that you want to change the default for program.

    5. click on the extension of the file to select it, once you have found what you are looking for.

    6. click the button of change... program above the scroll bar.

    The Open with dialog box should appear.

    7. look into options for programs recommended and choose the application you want to open it with the file extension when you double-click on the particular type of the file on your computer.

    Note: Chances are, requests described under the programs recommended will be contain more programs for this type of file, but don't forget to look at the applications under other programs. You may need to click the v to expand the list of these programs.

    Note: Click Browse... to search, through your computer for any program not shown do not want to use.

    8. click OK in the Open with window. Windows 7 is going to update the list of file associations to display the new default program to open this type of file.

    9. click the button close the bottom together associations . You can also close the window of the Control Panel if it is still open.

    10. at this stage, when you double-click on any file with this particular file extension, the program you partner in step 7 will launch and load the particular file.

    Important: Program used to automatically open when these types of files have been launched will again open these types of files. To use a different program, you just need to start the program manually and then browse your computer for the file in particular.

    If please reply back and let us know if know if it helped to solve your problem or if you still need help.

    Sincerely,

    Marilyn
    Microsoft Answers Support Engineer
    Visit our Microsoft answers feedback Forum and let us know what you think

  • Movie Maker grab and changed all the desktop icons for Movie Maker and all isopening Movie Maker

    I have a big problem, I have Windows 7 and I made a film using still photos on my computer now all binding, Movie Maker says that Movie Maker does not support the selected file type, 3 first films went great, but obviously I hit the wrong key, it changed all the icons on my desktop to display the icon of Movie Maker and each icon now opens on seizures to the top of Movie Maker, I tried every troubleshooting and restoration utility, but nothing changes; When I go to Movie Maker hand opens as if she's trying to do something. Can you give me any advice, would be much appreciated I can't do a thing right now.

    VI

    Have you tried to do a system restore
    Safe mode for one hour before the beginning of the question?

    Using Windows 7 or Vista System Restore
    http://www.howtogeek.com/HOWTO/Windows-Vista/using-Windows-Vista-system-restore/

  • I want to change all the adobe cloud programming language (I now use Korean but I want to change all the English program) is my computer OS

    I want to change all the adobe cloud programming language (I now use Korean but I want to change all the English program) is my computer OS

    Hi Parky22317382,

    Please follow the steps mentioned here https://helpx.adobe.com/creative-cloud/help/change-install-language.html

    Let us know if it works!

  • How can I change a page of my document from portrait to landscape without changing all the pages

    Acrobat Reader DC - How can I change a page of my document from portrait to landscape without changing all the pages?

    Hello Tracy,.

    You must use Acrobat Pro DC to do it with the help of the Pages organize the toolset.

    Thank you

    Abhishek

  • I have install Adobe DC pro but the leguage is Spanish. I like to change all the menus in German. How do I do this?

    I have install Adobe DC pro but the leguage is Spanish. I like to change all the menus in German. How do I do this?

    Install the German version of the product.

  • How to stop Nitro file converter to change all the files Adobe

    Recently, I wanted to convert a word document to PDF format and downloaded a free version of the Nitro program, but as the only free part of the downloaded program had to watch as she then asked me to purchase the full program before I can use it so I deleted it from my computer. But before he completed the uninstall is it changed all the Adobe files and documents that I had on my computer as it now changes the file type of any Adobe file or document sent to me as an attachment.  How can I stop it? Drag the manufacturer before the courts sort them? If anyone has any ideas on how to prevent or change what happened to be sent to the email address [email protected]

    Hi 117elk,

    I'm sorry to hear that you are having problems with your Adobe files. But I think it will be an easy fix. You should be able to re - associate files with their correct application names. I'm tons of course what operating system, you are on, but here are the instructions for many:

    Change the programs that Windows uses by default - Windows help

    How to change the default application for a file type. Macworld

    Please let us know how it goes.

    Best,

    Sara

  • Installation of photoshop elements Associates/changed all the files on the computer for photoshop elements files

    I bought Photoshop Elements for my mother while hospitality during Thanksgiving. When I installed it on his computer, it changed all the files on his computer for photoshop elements files, or rather, it combined all the files in photoshop elements. I don't know that it is an operating system problem. Can someone tell me why this is happening and give me a cure? It uses Windows 7. It is a 64-bit computer, if it's important.

    Thanks for any advice.

    Andy

    Hi Andy,.

    Please, try the steps mentioned in the link below and check out them.

    http://helpx.Adobe.com/Acrobat/KB/application-file-icons-change-Acrobat.html

    Kind regards

    Anand

  • Function to change all the form_specification in call_form

    Hi all

    I'll try to find a solution to change all the form_specification in call_form for an entire application, is possible to create a function or what... It is not effective to do by hand.


    Thank you!
    Micro

    THE: the arrest of is move my aplication of Win Linux server

    Published by: user10423661 on August 4, 2011 23:47

    If you don't have the appeal of the form in a procedure in a library?

    One way would be to update your code with JDAPI to substitute call_form instruction in all pl/sql in modules (and I'd do it for a procedure of Central Library).

    Steve

  • How to change all the colors specific to another color.

    Can someone tell me how to change all the colors in Illustrator by another color at a time.

    I've worked in Freehand, and you can select all, go in a Panel and make the change

    all from one color to another in a layout.

    Exp. You can change pms 356 to pms 410 without selecting each one individually.

    I can't find this feature in Illustrator CS4

    Any help appreciated

    HJMann42

    Left is simple to do, said Kurt.

    Go to the Swatch Panel, select pms 401 that cmd select pms 356 go to the menu drop down and select Merge shades.

  • How to change all the level made of stored for dynamic calc

    Hi all

    I have about 500 members of a level and I want to change their property of stored in dynamic Calc.
    I have not the dimension generate files and my outline extractor does not work (throwing an error from the api).
    Is he in any case other than these I can do without dimension of generation files? (with a new file of rules etc.)

    Thank you.

    First, the error from the API may be a known issue with outline Extractor:

    http://www.appliedolap.com/files/olapunderground/outline-Extractor/Essbase%20error%201042006%20when%20customer%20tries%20To%20do%20too%20many%20connections%20from%20one%20machine.PDF

    Or you can update the members directly from the sketch in the EA. And you can select several members by using the ctrl or SHIFT keys to change all the properties at a time.

    Or you can retrieve the members in Excel, click format for a dim build file that modifies the property.

Maybe you are looking for

  • Satellite L850 - need to correct hd7670m AMD driver

    http://www.toshibamea.com/TechnicalSupportDetails.aspx?PageID=21&ProductID=5 1275So my laptop and iam having problems, find the correct drivers and CCC to my gpu... I need CCC because of "underscan" which occurs on my second monitor. Windows generic

  • Toshiba DR570 - need help to identify a DVD burner

    I recently bought a Toshiba DR570 and have been very happy with it so far.The only problem I have is that I can't get my DVD from PC Player to see the disc.Not even after a firmware upgrade on my older PC, any more than see it my new laptop. I also t

  • I get a white screen when I try to resume the computer from the stand-by.

    When I try to wake up my Windows XP after standby by pressing the space bar, he falls down and leaves me with a white wallpaper screen. I have to pull the plug to get by, then again upward. What can I do? -RR Original title: die waiting

  • Computer hangs during POST

    original title: everytime I restart my computer it freezes on the, select DEL to enter set upwards or TAB to continue, the page. He acts as if there is no connection with the keyboard. If I pull the small battery shows off the motherboard then it hig

  • BB Curve 8350i to blackBerry Smartphones using public calendars?

    Hello, 1st time poster... I just upgraded to the BB Curve 8350i on a BES Server v4.1.6.9 and I was wondering if there was a way to add another calendar, I use a "schedule of public folders" for my appt business and would like to synchronize with the