Table Splitting question / system copy

[martin_juen2]

Hi,

we are migrating from Oracle DB on AIX to Exadata. The database is ~5 TB, the biggest table is CE10200 with 550 GB.

Report UMG_R3LOAD_RUNTIME_PREDICTION recommends a split factor 6 for this table.

I think this factor is too small. Does anyone have a reference for splitting tables? 90 GB for one package seems too large for me. I think 10 - 15 GB is a better value but i can't estimate the impact to the db performance / export performance when splitting the table to 50 packages.

I can't find a best practise for this topic. Maybe we can document a reference here

Thanks for your help.

Martin

[stefan_koehler]

Hi Martin,

i have chosen a table splitting size of round about 10 GB in most of my multi tera byte migrations.

However i used migration monitor with Oracle access path adjustments (like view definitions with parallel query) to get a good export performance. But all kind of definitions and performance optimizations depend on the environment and downtime requirements as Michael already mentioned.

For example it makes no sense to split a table into several hundred packages, if you are running 10 R3load processes only, because of your "export application server" has not enough CPU resources. Please consider the access path for all export processes and the waiting "post import" tasks (like index creation) on such objects as well.

Regards

Stefan