Oracle Hcc Compression

Hybrid columnar compression is performed by Exadata only - so it does not apply to "regular Oracle " - just the Exadata Database Machine. Basically - we store data in what is called a compression unit - a set of blocks. So, unlike basic and advanced compression - which both work block by block and each block is 'self contained', you need only

https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:2852001100346111839

Perform these steps to enable Hybrid Columnar Compression (HCC) on Direct NFS Client: Ensure that SNMP is enabled on the ZFS storage server. For example: $ snmpget -v1 -c public server_name .1.3.6.1.4.1.42.2.225.1.4.2.0 SNMPv2-SMI::enterprises.42.2.225.1.4.2.0 = STRING: "Sun Storage 7410". If SNMP is enabled on an interface other than the NFS

https://docs.oracle.com/en/database/oracle/oracle-database/19/ladbi/enabling-hcc-on-direct-nfs-client.html

The Compression Unit. Under HCC Oracle uses a structure called a Compression Unit. If you look at how Oracle stores a compression unit it is, in a very real sense, stored as a single row. The number of columns in that one row is ...

https://jonathanlewis.wordpress.com/2012/07/20/compression_units/

An Oracle Technical White Paper . May 2014 . Implementing Hybrid Columnar Compression on the Oracle ZFS Storage Appliance . Synopsis: Hybrid Columnar Compression is a unique and effective compression option for

https://www.oracle.com/technetwork/server-storage/sun-unified-storage/documentation/problemsolver-hcc-52014-2202692.pdf

The introduction of support for HCC Compression for Array Inserts in Oracle Database 12.2.0.1. Hybrid Columnar Compression (HCC) can now be used during array inserts into tables. This means that the SQL INSERT SELECT statement without the APPEND hint can use HCC, and array inserts from programmatic interfaces such as PL/SQL and the Oracle Call

https://support.oracle.com/knowledge/Oracle%20Database%20Products/2469912_1.html

In EHCC we may have a table to have mix of HCC and OLTP compression . Does this create extra overhead with fetching data when range scan is used ?u001f. Is the row migrated out of CU when update occurs causing row migration u001f? u001fDefault segment size is 8MB, can EHCC compression make it less than 8MB ?u001f.

https://support.oracle.com/knowledge/Sun%20Microsystems/1910687_1.html

TEST 2: HCC segment status after virtual to physical Using same dSource that was used for TEST 1, we provisioned a VDB (BIZDHCC1) in an Exadatata node. This VDB has a table with Hybrid Columnar Compression for Query High: SQL> select table_name , compression , compress_for from dba_tables where owner='501677820';

https://community.delphix.com/blogs/diego-loureda/2019/09/09/some-interesting-facts-about-oracle-hcc-hybrid-columnar-compression