Data Class in ABAP dictionary

[Former Member]

hi,

recently we moved the tables from tablespace PSAPBTAD to user defined tablespace & since than we have poor performance in PROD - have any one had this issue before ? any idea on data class and tablespace ?

thanks

[Former Member]

If you used brtools or sapdba for the reorg then the data class will be handled automatically. Shouldn't be a problem. Maybe checking disk io would be a good idea...possibly the datafiles for the new tablespace are on hot volumes and could simply be moved to another volume group (assuming you're on a SAN).

[Former Member]

hi Jason,

thankx for the reply - we used third party tool reorg and since than we have lot of performance issue any idea on this why this happing.

[Former Member]

I doubt data class affects performance. It definitely affect upgrades and support packs so you'll want to confirm that every table you reorged is assigned the data class associated with its current tablespace, otherwise you can lose data.

It could be a lot of things affecting the performance. Maybe the reorg tool added too many small extents to the tables which is a problem only if you're not on SAN and if the tablespaces are DTMS. But I'd start with disk stats. Take a look and see if you've got hot spots, it's the first thing I'd check.

Oh, and how about database statistics, did you re-calc after the reorgs? It's essential.

[Former Member]

we did ran the database statistics after reorg , can give on hot spots were to look for them ?

[Former Member]

quick glance at ST04 -> Detailed Analysis -> File system Requests which is just v$filestat assuming you're on Oracle.

You are using Oracle?

There are other checks in SAP but personally I'd first ask the sysadmins to check sar assuming you're on unix and the storage team to check the SAN. hotspots are easier to see with those tools.

[Former Member]

Jason,

Thanks for the response - i will check with other team.

regards