Compression for tables with more than 250 columns
Tables with more than 250 columns are not supported to be compressed, this restriction remains in place even on 11g R2.
On the 11g R2, Sql Language Reference Manual, page 16-36 we can read:
Restrictions on Table Compression
* COMPRESS FOR OLTP and COMPRESS BASIC are not supported for tables with more than 255 columns.
This is a serious limitation specially for Telecoms where CDR tables can have a number of columns way over 255.
The available workaround:
- create table A as select pk,field 1 to 150 from origtable
- create table B as select pk,field 151 to 300 from origtable
- create view origtable as select a.pk,field a.1 to a.150, field b.151 to b.300 from a, b where a.pk=b.pk