HCC and parallel

Hello,

we use an Exadata X3-2 with January 2014 patch and all software of version 11.2.0.4. Imageinfo shows 11.2.3.3.0.131014.1.

We have one big OLTP compressed table CALLS_00. It has about 2K partitions and contains calls records CDR, original size is 2811g for September and 2980g for October.

We compress it into HCC and we have strange results: for different parallel we have a very different HCC size.

We compressed the September in Archive High:

for 8 parallel slaves we've got 394g HCC AH size

for 32 parallel slaves we've got 718g HCC AH size

for 64 parallel slaves we've got 1400g HCC AH size