You plan to migrate a database supporting both DSS and OLTP workloads to your new X5 Database machine.
The workloads contain many complex aggregating functions and expensive joins on large partitioned tables in
the DSS workload and indexed access for OLTP workloads.
Which three benefits accrue as a result of this migration?
A.
Superior compression capability designed specifically for OLTP workloads
B.
Columnar storage capability for data in row major data blocks that is held in flash cache
C.
Superior compression capability designed specifically for data warehouse tables
D.
Superior compression capability designed specifically for archival data
E.
Superior flash cache compression technique
F.
Cell offload processing for indexed-organized table access
Explanation:
There are 6 different kinds of Table Data Compression methods:1. BASIC compression, introduced in Oracle 8 already and only recommended for Data Warehouse
2. OLTP compression, introduced in Oracle 11 and recommended for OLTP Databases as well
3. QUERY LOW compression (Exadata only), recommended for Data Warehouse with Load Time as a critical factor
4. QUERY HIGH compression (Exadata only), recommended for Data Warehouse with focus on Space Saving
5. ARCHIVE LOW compression (Exadata only), recommended for Archival Data with Load Time as a critical factor
6. ARCHIVE HIGH compression (Exadata only), recommended for Archival Data with maximum Space Saving
Incorrect Answers:
B:
1. BASIC compression, introduced in Oracle 8 already and only recommended for Data Warehouse
2. OLTP compression, introduced in Oracle 11 and recommended for OLTP Databases as well
3. QUERY LOW compression (Exadata only), recommended for Data Warehouse with Load Time as a critical factor
4. QUERY HIGH compression (Exadata only), recommended for Data Warehouse with focus on Space Saving
5. ARCHIVE LOW compression (Exadata only), recommended for Archival Data with Load Time as a critical factor
6. ARCHIVE HIGH compression (Exadata only), recommended for Archival Data with maximum Space Saving
Method 1 and 2 are working by compressing the rows inside of Oracle Blocks – the more redundant values inside the block, the better the compression ratio. OLTP compression might be used with Exadata Database
Machine, because Exadata V2 is designed to support OLTP as well as Data Warehouse. Methods 3 to 6 use
Hybrid Columnar Compression (HCC), which is designed to achieve better compression ratios by organizing sets of rows into compression units and then detaching the columns from the rows and collecting them. It is more likely that the same columns store similar (redundant) data, therefore the compression ratio improves with
HCC.
References: https://uhesse.com/2011/01/21/exadata-part-iii-compression/