AUTO_COMPRESSION not working

[Former Member]

Hi Guys,

I have 2 identical tables each containing 183 mio records.

One of them is compressed and the other isn't.

The compressed table takes up 16 GB in memory the other 55 GB.

If I look in m_cs_columns under compression_type table 1 has different types for each column (RLE,CLUSTERED,INDIRECT,PREFIXED)

and table 2 has compression_type DEFAULT in all columns.

My guess is that the evalutation of compression_type hasnt run. Because the optimization works fine on the first table.

In table "tables" both tables have AUTO_OPTIMIZE_COMPRESSION_ON set to TRUE and are otherwise totally identical.

Is there any way i can initiate this optimization by a command?

Or do you have any other suggestions?

Best Regards

- Rasmus

[Former Member]

Please have a look at SAP Note 2112604 (FAQ: SAP HANA Compression). The question "What do I have to take into account in order to make sure that the tables are compressed optimally?" describes typical problems and how to trigger / force a compression manually.