Re: archiving table-data

(Real E-mail: altena_at_gol.com)

Getting the data out of oracle and deleting it, is no problem. You could face a few Oracle messages if your rollback segment is to small (or the amount of data you want to delete is to large). But that is just a matter of either increasing the rollback segment or inserting a few "commit" statements in the client app. that will delete the old data. Since deleting old data is not something that happens every day, my vote goes to inserting the commit statements. (You will only start the delete process once you know that your data was archived succesfully anyway)

now, if your measurement data looks something like this:

   -SensorID
   -TimeStamp
   -MeasuredValue

Then i would recommend using a so called "OLE-compound document" to archive the data. The file will look something like this:

Filename

    |

    -----SensorID(1)                      <--a seperate steam for each sensor
             |


             -- Timestamp, MeasuredValue 

             -- Timestamp, MeasuredValue 

             -- Timestamp, MeasuredValue 

             ...
    -----SensorID(2)
             |


             -- Timestamp, MeasuredValue 

             -- Timestamp, MeasuredValue 

             -- Timestamp, MeasuredValue 

             ...

This is working fine for us.

    Robert Altena

bacher wrote:

> 
> hello,
> 
> I have a very large table (>2GB) containing measurement-data, now I want
> to archive all rows, which are older than n hours, to tape. anyone knows
> if there are some standard products existing for archiving data, or what
> is the best way to do that?
> 
> thanks,
> 
>         --heiko--