R3load unsorted export questions

[BSG]

Hi,

To speed up a heterogenous systemcopy & UC conversion (OS change, database oracle) I am looking into unsorted unloading / loading. I have read note 954268. I still have some questions on this though.

Are there any drawbacks on performing unsorted unloads? Or is it advised to always perform unsorted unloads (except for cluster tables)? If I perform an unsorted unload, will the load take longer if I perform it sorted? Is it possible to perform unsorted loads (and does this make sense)?

What are the experiences with this?

Thanks,

Regards,

Bart

[markus_doehr2 · Accepted solution]

> Are there any drawbacks on performing unsorted unloads? Or is it advised to always perform unsorted unloads (except for cluster tables)? If I perform an unsorted unload, will the load take longer if I perform it sorted? Is it possible to perform unsorted loads (and does this make sense)?

I certainly would do a few test runs and check the performance on your system environment. Also be aware that you must have a certified migration consultant on-site if you perform a heterogeneous copy.

Unsorted unloads are faster than sorted ones.

Markus

[BSG]

Finally decided to perform a sorted export.

Thanks,

Regards,

Bart.

[Former Member]

Hello Bart...so how was the overall runtime using sorted?  Was it much longer than unsorted? 

[BSG]

Hi Dawn,

Since tests showed that sorted export would fit in our migration weekend we decided to just use sorted exports.

Regards,

Bart

[BSG]

Hi Markus,

Thanks for your reply.

I will definitly test and optimize the migration. However, I am wondering if there are any drawbacks in using the unsorted unload. E.g. when the data is reloaded in the target database or on the performance of the target database if the records are not sorted.

Thanks,

Regards,

Bart

[sunny_pahuja2]

Hi,

Check below link to check pros and cons of unsorted export:

http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/8091fedf-5346-2a10-e4a0-a3cafe860...

Thanks

Sunny

[volker_borowski2]

>

> However, I am wondering if there are any drawbacks in using the unsorted unload. E.g. when the data is reloaded in the target database or on the performance of the target database if the records are not sorted.
> Regards,
> Bart

Hi,

In general 80% of the benefit comes from cleaning up fragmentation and giving

you better read ratio because of better cache quality.

There are just rare cases, where it helps to do a sort for the primary key

(which R3load is doing). The most obvious benefit for the unsorted export is,

that you save PSAPTEMP resources on the SOURCE metall.

So less need to buy new disks for the old box !

If you really desire a sorted table, do a reorg right after the migration

on the new metall. Will be more speedy and you'll have resources there anyway.

(And let me know which table this might be, I had none yet)

Best regards

Volker