How to detect data errors?

In applications such as healthcare, errors in data stored in a database could lead to so called Adverse Events even death of a patient. Clearly, if erroneous data could be detected then the user could be warned not to trust what is displayed.
So, what happens in practice? If hardware failure or flawed software were to cause occasional data errors in a Oracle Database, would such errors be detected by the database engine or is detection left to the application? For example, a single bit error relating to an index that is supposed to be unique or a field containing a code representing a patient's blood type. When would this violation of integrity be detected and how would such errors become evident? Is it credible that such errors could cause incorrect data to be returned from a query?
Clearly CRC or hashing functions could be called using appropriate triggers to provide field or record level error detection.
1. Is anyone doing this?
2. What is the recomended approach ?
3. What is the performance penalty likely to be?
4. Is there any documentation that describes this ?
Thanks,
James

Hi,
you have two parameters called DB_BLOCK_CHECKSUM and DB_BLOCK_CHECKING, which calculate checksums by reading (DB_BLOCK_CHECKING) and writting (DB_BLOCK_CHECKSUM)
Some storage vendors like Hitachi work closely with Oracle to provide additional protections against data corruption. Look for the Oracle H.A.R.D. initiative at http://otn.oracle.com/deploy/availability/htdocs/vendors_hard.html
You will then find documentation on the storage vendor site as well.
Regards
Laurent Schneider
OCM DBA

Similar Messages

How to detect an error from ajax get

Hi -- This is in a javascript function.
I have an object ajaxRequest defined as:
ajaxRequest = new htmldb_Get(null,&APP_ID.,'APPLICATION_PROCESS=LOOKUP_VALUE',0);
I call the app process as follows:
ajaxResponse = ajaxRequest.get();
The app process just looks up a value in the DB based on another. It works fine
when there's a match. When there's not a match, I can see that the ajaxResponse
contains "sqlerrm: ORA- ... ". And of course a json.parse fails.
How can I detect that the get returned an error? I can't just search
ajaxResponse for an string, right? (It doesn't appear that that object is
simply treated as a string... )
Thanks,
Carol

hi John -- Sounds good, but I guess I'm not sure how to go about it.
LOOKUP_VALUE is:
DECLARE
-- Set wwv_flow.g_x01, g_x02, g_x03, g_x04 and g_x05 in the
-- javascript part
p_source_item_value varchar2(1000) := wwv_flow.g_x01;
d_source_column_name varchar2(32) := wwv_flow.g_x02;
d_dest_column_name varchar2(32) := wwv_flow.g_x04;
d_lookup_table_name varchar2(32) := wwv_flow.g_x05;
BEGIN
--Use this to get a JSON string back in the javascript,
-- based on the SQL query
APEX_UTIL.JSON_FROM_SQL('SELECT '||d_dest_column_name||' RETURN_VAL FROM '||d_lookup_table_name||'@'||:DB_NAME||' WHERE '||d_source_column_name||' = '''|| p_source_item_value||'''');
END;
So, it's returning this JSON object to the javascript. As I said, it works fine when there's a match.
I'm not sure how to catch an error in the LOOKUP_VALUE process and get it back to the javascript. Ideas?
Also, even if I do get that going, I'm not sure how to check the returned object for some sort of problem.
The javascript function code is below. Look for #### for my comments. Essentially, right now, if
there is an error in the json object (it's showing up as a numeric or value error), the parse fails. So I
need to detect the problem before the parse. OR, if I can just modify LOOKUP_VALUE to plug in
something like 'NO MATCH' when there's a problem or no value is found, then I think json.parse will work
and my page item can just be set to NO MATCH. Does this make sense?
Here's the function.
Thanks for your help!
Carol
function jsLookupValue(source_item_value, source_column_name, dest_item_name, dest_column_name, lookup_table_name){
// Continue only if there are valid values
if (valueOf(source_column_name)&&valueOf(dest_item_name)&&valueOf(dest_column_name)&&valueOf(lookup_table_name)){
//Check to see if the source_item_value is null (either all spaces or empty
//If it is, set the dest item to null, but only if it's not already --
//otherwise we get into a loop.
source_item_value = trim(source_item_value);
dest_item_value = trim($v(dest_item_name));
if (source_item_value.length==0) {
if (dest_item_value.length != 0) {
$s(dest_item_name, null);
}else{
//This is the AJAX call to the Application Process from step 1
ajaxRequest = new htmldb_Get(null,&APP_ID.,'APPLICATION_PROCESS=LOOKUP_VALUE',0);
//Here we are adding that x01 parameter we use in the app process with the value of the objecttype_name field
ajaxRequest.addParam('x01', source_item_value);
ajaxRequest.addParam('x02', source_column_name);
ajaxRequest.addParam('x03', dest_item_name);
ajaxRequest.addParam('x04', dest_column_name);
ajaxRequest.addParam('x05', lookup_table_name);
//Now do the actual AJAX call and put the result in ajaxResponse
ajaxResponse = ajaxRequest.get();
//Check if there is a response
if (ajaxResponse) {
// ######### When there's no row matching the query, this alert shows
// "sqlerrm: ORA-06502 PL/SQL: numeric or value error"
// Can I somehow check ajaxResponse for that string?
alert("Response from APP process: " + ajaxResponse);
//We need to format the JSON return string and put it in a JSON object
// the formatting is done by a function in the external JSON library
// the jsonobj can be used to retrieve the data returned by the App process
// ######### If there was an error, the parse fails
var jsonobj= ajaxResponse.parseJSON();
alert('Filtered returned value from APP process: ' + jsonobj.row[0].RETURN_VAL);
// And finally, we set the DNAME item with the value of the jsonobj.DNAME
// an array was created in the object with the name row, so that is why you have to include row[0] to retrieve the data
if (jsonobj.row[0].RETURN_VAL != $v(dest_item_name)) {
// ########## I'd like to just set the destination item w/ something like "NO MATCH"
// probably regardless of the error...
$s(dest_item_name, jsonobj.row[0].RETURN_VAL);
}else{
//alert ('NOT setting dest item');
} //not setting
}else{
alert('No response from app process');
} //no response
} //no source item value
} //no bad nulls
} //function

How to catch date errors and continue processing in a PL/SQL procedure

I'm updating a date field with dates constructed from day, month and year fields. The incoming data has many instances of day and month that are not valid dates, ex 11 31 2007. There is no 31st day in November.
I would like to write a pl/sql script to scan the table containing these values and log the rows that produce conversion errors.
I thought I could do this with exceptions but there are no exceptions that correspond to the ORA-01847 error for mismatched day and month.
Here is what I tried (the print procedure is a local wrapper for DBMS_OUTPUT.put_line):
PROCEDURE date_check IS
start1 DATE ;
BEGIN
select to_date(nvl(yearcollected,'9999') ||'/'|| nvl(monthcollected,'01') ||'/'|| nvl(daycollected,'01'),'YYYY/MM/DD'))) into start1 from incoming_data where id=1 ;
     BEGIN
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     EXCEPTION
          WHEN OTHERS THEN
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     END;
print('Processing continues after handling date exception') ;
END date_check ;
Is there a way to catch this kind of error and continue processing after logging a message?
-=beeky

Hi, Beeky,
There are lots of different error messages associated with bad dates. Rather than try to catch them all, I use a BEGIN ... EXCEPTION block that contains nothing but a TO_DATE call. This is one of the rare occassions when I think "EXCEPTION WHEN OTHERS" is okay,
The following function comes from a package. If you want to make a stand-alone function, remember to say " *CREATE OR REPLACE* FUNCTION ...".
--          **   t o _ d t   **
--     to_dt attempts to convert in_txt (assumed to
--          be in the format of in_fmt_txt) to a DATE.
--     If the conversion works, to_dt returns the DATE.
--     If the conversion fails for any reason, to_dt returns in_err_dt.
FUNCTION     to_dt
(     in_txt          IN     VARCHAR2                    -- to be converted
,     in_fmt_txt     IN     VARCHAR2     DEFAULT     'DD-MON-YYYY'     -- optional format
,     in_err_dt     IN     DATE          DEFAULT     NULL
RETURN DATE
DETERMINISTIC
AS
BEGIN
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     RETURN     TO_DATE (in_txt, in_fmt_txt);
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     WHEN OTHERS
     THEN
          RETURN in_err_dt;
END     to_dt
;

Create Procedure - How to Detect Compilation Errors

Hi,
I am working on an application where users will be able to type in their own stored procedures. I perform some basic parsing of the function spec, to make sure it is well-formed, but that's all the parsing I do. I assumed an SQLException would be thrown by the executeUpdate() call which creates the procedure if the procedure is malformed. This is not the case. executeUpdate() returns 0, whether or not the procedure was created with compilation errors.
After they type it in, I would like to be able to tell the user whether or not their procedure is syntactically correct. Given that writing a complete PL/SQL parser in Java is obviously out of the question, how can I do this? There must be a way.
Thanks in advance for any and all help,
James

Note that there is a USER_ERRORS table.
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How to detect conversion errors due to charset mismatch client/server?

If a character cannot be converted by OCIStmtExecute (Bind Variable) and/or OCIStmtFetch (Into Variable), either a replacement character (usually question mark) or a similar character (e.g. è -> e) is used instead.
I am looking for a possibility to get an indicator flag if a column could not be converted between client character encoding (NLS_LANG setting) and database encoding (NLS_CHARACTERSET).
If I do the conversion in my code, setting OCI_ATTR_CHARSET_ID to OCI_UTF16ID and using OCICharSetToUnicode(), OCIUnicodeToCharSet() and OCICharSetConversionIsReplacementUsed(), this would be quite a bit of work, allocating extra buffers, and it detects only conversion errors during OCIStmtFetch (into variables), not for bind variables during OCIStmtExecute.

If a character cannot be converted by OCIStmtExecute (Bind Variable) and/or OCIStmtFetch (Into Variable), either a replacement character (usually question mark) or a similar character (e.g. è -> e) is used instead.
I am looking for a possibility to get an indicator flag if a column could not be converted between client character encoding (NLS_LANG setting) and database encoding (NLS_CHARACTERSET).
If I do the conversion in my code, setting OCI_ATTR_CHARSET_ID to OCI_UTF16ID and using OCICharSetToUnicode(), OCIUnicodeToCharSet() and OCICharSetConversionIsReplacementUsed(), this would be quite a bit of work, allocating extra buffers, and it detects only conversion errors during OCIStmtFetch (into variables), not for bind variables during OCIStmtExecute.

How to detect CPU error in SMP system?

I want to monitor if the CPU is working properly in real-time, especially at SMP system. My goal is to build a program that shows "CPU n is working properly" and if one is down, showing "CPU n down".
Is there pre-defined C function I can use? Or is there better one?

I think that kstat() does such a function, but for SMP system, how does it work? Is there a certain way to specify CPU?

How do I view Migrate Data errors - Access 2003 - Oracle 10g

I'm trying to use the SQL Developer to migrate data from an Access 2003 database to an Oracle 10g database. I followed the instructions found here:
http://www.oracle.com/technology/tech/migration/workbench/files/omwb_getstarted.html
I was able to complete every step except the actual data move. I exported the xml for the Access database, I captured the export and then ran the generation scripts on my target Oracle database (I'm using the same schema for the migration repository and the actual data). It created the tables with only one or two errors which I resolved.
Now, when I select Migration->Migrate Data, I get the dialog that appears to start 4 or 5 threads and attempts to migrate each table. They all error and do not transfer any rows. I can see that there's one error per table, but I can't see the error text. I just know that an error occurred. Is there a log somewhere or is the error displayed somewhere else? How do I know what's gone wrong?
Thanks.

I too receive unexplained error counts using the Migrate Data menu selection and unexplained failures using the Generate Data Move Scripts menu selection. Permissions granted by role or direct grants should not be a problem, but a Migrate Data error appears in the Migration Log panel at the bottom of the SQL Developer window, "Failed to disable constraints: ORA-00942 ... ". No further details available on what constraints or why the error. No other errors were detected while following the instructions found in the Oracle SQL Developer Migration Workbench Getting Started guide. SQL Developer never migrates the data from the existing Access 2000 mdb file to the newly created schema objects in Oracle 10g using either method. The following roles and privileges have been granted to both the repository owner and the target schema owner:
GRANT RESOURCE TO MIGRATE_USER WITH ADMIN OPTION;
GRANT CONNECT TO MIGRATE_USER WITH ADMIN OPTION;
ALTER USER MIGRATE_USER DEFAULT ROLE ALL;
-- 25 System Privileges for MIGRATE_USER
GRANT CREATE ROLE TO MIGRATE_USER;
GRANT ALTER TABLESPACE TO MIGRATE_USER;
GRANT ALTER ANY SEQUENCE TO MIGRATE_USER;
GRANT INSERT ANY TABLE TO MIGRATE_USER;
GRANT SELECT ANY TABLE TO MIGRATE_USER;
GRANT CREATE ANY TABLE TO MIGRATE_USER;
GRANT UNLIMITED TABLESPACE TO MIGRATE_USER WITH ADMIN OPTION;
GRANT DROP TABLESPACE TO MIGRATE_USER;
GRANT CREATE ANY TRIGGER TO MIGRATE_USER;
GRANT ALTER ANY ROLE TO MIGRATE_USER;
GRANT CREATE VIEW TO MIGRATE_USER WITH ADMIN OPTION;
GRANT DROP USER TO MIGRATE_USER;
GRANT CREATE TABLESPACE TO MIGRATE_USER;
GRANT GRANT ANY ROLE TO MIGRATE_USER;
GRANT CREATE ANY SEQUENCE TO MIGRATE_USER;
GRANT ALTER ANY TABLE TO MIGRATE_USER;
GRANT DROP ANY TRIGGER TO MIGRATE_USER;
GRANT DROP ANY ROLE TO MIGRATE_USER;
GRANT DROP ANY SEQUENCE TO MIGRATE_USER;
GRANT UPDATE ANY TABLE TO MIGRATE_USER;
GRANT ALTER ANY TRIGGER TO MIGRATE_USER;
GRANT COMMENT ANY TABLE TO MIGRATE_USER;
GRANT DROP ANY TABLE TO MIGRATE_USER;
GRANT CREATE PUBLIC SYNONYM TO MIGRATE_USER WITH ADMIN OPTION;
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ALTER USER MIGRATE_USER QUOTA UNLIMITED ON USERS;
Operating system for both Access 2000 and Oracle 10g is Windows XP PRO SP2.
Oracle SQL Developer is version 1.1.2.25 build MAIN-25.79 on Windows XP PRO SP2. All three are on the same PC.
Since only the last step failed, I created a User DSN with the ODBC administrator. Then, linked the newly created Oracle table to Access via ODBC using the DSN created. Next, I created an append query with the source being the Access table and the target being the Oracle table. I moved the data by pressing the red exclamation mark.

On closing Acrobat Windows detect an error "Data Execution Prevention has closed Adobe Acrobat".

Hi,
I developed a plugin which captures Before/After open, close and save events and perform some operation inside these events.
I tested the plugin in Windows XP and Acrobat 9.0.0 and 10.0.0 and everything works fine. But when in test my plugin on Windows Server 2008 Standard 32 bits, then windows detect an error while closing the acrobat and shows the following message:
"Data Execution Prevention has closed Adobe Acrobat"
I am using Acrobat 10.0.0 for testing in Windows Server 2008 operating system. Also, debugging the program shows no error but plugin does not produce the desired result when tested on Windows Server 2008 Standard 32 bits operating system.
Can anyone please giude me how to resolve this issue??
Thanks in advance!

Are you really using 10.0.0? You've installed no updates to it??
From: poortip87 <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Date: Mon, 6 Feb 2012 21:46:02 -0800
To: Leonard Rosenthol <[email protected]<mailto:[email protected]>>
Subject: On closing Acrobat Windows detect an error "Data Execution Prevention has closed Adobe Acrobat".
On closing Acrobat Windows detect an error "Data Execution Prevention has closed Adobe Acrobat".
created by poortip87<http://forums.adobe.com/people/poortip87> in Acrobat SDK - View the full discussion<http://forums.adobe.com/message/4190399#4190399

I am using Windows 8.1 i have an External Hard Disk and one drive is now inaccessible due to sudden power failure few days ago. Now it shows "Data error (Cyclic redundancy check)". I want all my important files and Pics. How ?

Hi,
I am using Windows 8.1
I have an External Hard Disk i have partitioned it to 4 parts.
One drive is now inaccessible due to sudden power failure while listening Music from that drive few days ago.
Now it shows "Data error (Cyclic redundancy check)".
I tried all the procedures provided here like
chkdsk /f, diskpart, rescan etc
but no result :( (i mean all processes failed. They could not detect the drive).
Please help me to get those data, pictures and project files.
thank you

Then why aren't you posting this in the Windows 8 forums found @
http://social.technet.microsoft.com/Forums/windows/en-US/home?category=w8itpro
This is a Windows 7 forum for discussion about Windows 7.
Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

How to rectify the error message " duplicate data records found"

Hi,
How to rectify the error "duplicate data records found" , PSA is not there.
and give me brief description about RSRV
Thanks in advance,
Ravi Alakunlta

Hi Ravi,
In the Info Package screen...Processing tab...check the option Do not allow Duplicate records.
RSRV is used for Repair and Analysis purpose.
If you found Duplicate records in the F fact table...Compress it then Duplicate records will be summarized in the Cube.
Hope this helps.

How to rectify the errors in master data loads & transactional data loads?

hy,
please any one tell me
How to rectify the errors in master data loads & transactional data loads?
thnQ
Ravi

Hi,
Please post specific questions in the forum.
Please explain the error you are getting.
-Vikram

How to edit inbound idoc with data errors in multiple segments and reproces

Hi friends,
i have a requirement for error handling of inbound sales order(ORDERS04) without using WORKFLOW and WE19.
i have seen some function modules like edic_* ..
but my doubt is how to edit the error data(how can i identify the particular error fileds in the segments)and how to reprocess the same idoc.
Please help me...
Thanks in advance

Hi Narasimh,
Please find the following steps to edit IDOC segment after you find the error using WE02.
The example codes can be found in website
http://www.sapgenie.com/sapedi/idoc_abap.htm
STEP 1 - Open document to edit
CALL FUNCTION 'EDI_DOCUMENT_OPEN_FOR_EDIT'
       EXPORTING
            document_number               = t_docnum
       IMPORTING
            idoc_control                  = itab_edidc
       TABLES
            idoc_data                     = itab_edidd
       EXCEPTIONS
            document_foreign_lock         = 1
            document_not_exist            = 2
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            OTHERS                        = 5.
STEP 2 - Loop at itab_edidd and change data
LOOP AT itab_edidd WHERE segnam = 'E1EDKA1'.
e1edka1 = itab_edidd-sdata.
IF e1edka1-parvw = 'LF'.
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ENDIF.
ENDLOOP.
STEP 3 - Change data segments
CALL FUNCTION 'EDI_CHANGE_DATA_SEGMENTS'
           TABLES
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                data_record_not_exist   = 2
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       EXPORTING
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       EXCEPTIONS
            idoc_not_open                = 1
            direction_change_not_allowed = 2
            OTHERS                       = 3.
STEP 4 - Close Idoc
Update IDoc status
CLEAR t_itab_edids40.
t_itab_edids40-docnum      = t_docnum.
t_itab_edids40-status      = '51'.
t_itab_edids40-repid       = sy-repid.
t_itab_edids40-tabnam      = 'EDI_DS'.
t_itab_edids40-mandt       = sy-mandt.
t_itab_edids40-stamqu      = 'SAP'.
t_itab_edids40-stamid      = 'B1'.
t_itab_edids40-stamno      = '999'.
t_itab_edids40-stapa1      = 'Sold to changed to '.
t_itab_edids40-stapa2      = t_new_kunnr.
t_itab_edids40-logdat      = sy-datum.
t_itab_edids40-logtim      = sy-uzeit.
APPEND t_itab_edids40.
CALL FUNCTION 'EDI_DOCUMENT_CLOSE_EDIT'
       EXPORTING
            document_number = t_docnum
            do_commit        = 'X'
            do_update        = 'X'
            write_all_status = 'X'
       TABLES
            status_records   = t_itab_edids40
       EXCEPTIONS
            idoc_not_open    = 1
            db_error         = 2
            OTHERS           = 3.
Hope this will help.
Regards,
Ferry Lianto

How to detect system date Format?

Could some one help to find out how to detect local system is in MM/DD/YYYY or DD/MM/YYYY format?
Thanks.

What happens when you run this code in a country where the default format is yyyy-MM-dd?
My advice is to either use the deault format for a given locale, or allow your app to be configured with a format.
demo:
import java.text.*;
import java.util.*;
public class RingingTheFormats {
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}What's going on in the Japanese format? What is H21?
edit: [Heisei |http://en.wikipedia.org/wiki/Heisei] period. nvm.

I updated iTunes to 10.4 version and now it doesn't start and sen a messages "iTunes has detected an error and must be closed". Someone have the same problem and how can we repair our installation insted of change the windows XP installation? Best regard

I updated iTunes to 10.4 version and now it doesn't start and send a messages "iTunes has detected an error and must be closed". Someone have the same problem and how can we repair our installation insted of change the windows XP installation? Best regards

Only way to get iMac starting again was to re-install 10.4.4 from DVD, and then update it into 10.4.6. For a while it worked perfectly, just as before.
Then I tried to print to CD with my EPSON Stylus Photo 950 from Adobe Photoshop Elements (2.0). It didn't print anything, but printer started flashing all lights. The print job was not performed, so I did remove it from the Printer Utility. After that the iMac started "ticking" again, same noise than before, after 10.4.7 installation. I did re-boot iMac. It never started, it does stuck on gray screen (gray block running clockwise). HW test from DVD didn't find any problems (extended search looping 3 times). But Disk Utility found hard drive to have inaccurate node structure, it could not fix it.
Apple support recommended to use DiskWarrior. However, it does not support (yet) Intel Macs. I haven't got TechTool Pro 4.5.1 anywhere. iMac does start on to FireWire mode (T at boot), but I cannot see the disk from 10.2.8 iMac.
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How to find flatfile errors while uploading data

hi all,
i hava a question... when i am uploading large amount of data (ex:1 lac records) in that 100 records are error records .. how to find the error records in flatfile before uploading.
regards shree.

Hi,
The only way to find out errors is to open the file from abap read through each record and validate it.
However , my approach would be to read through each record, validate it, if valid process it otherwise collect it in another auxilary internal table and then in the end log the errors for later processing.
regards,
Advait

How to detect data errors?

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