During my classes I often get the question "Can I see the Delta Merge?". The answer is "Yes". Below I have taken a screenshot from the "SHOP_FACTS" before and after a delta merge.
Looking at the table definition => Runtime Information I see that the table size is 12.8MB and contains it contains 88553 records.
- DeltaMerge01.jpg (79.41 KiB) Viewed 34281 times
After a delta merge the table size is 4.5MB and contains it still contains 88553 records. Also the compression due to storing the data in a columnar table is nicely visible.
- DeltaMerge02.jpg (79.48 KiB) Viewed 34281 times
Forced a delta merge with this sql statement:
Code: Select all
MERGE DELTA OF "EFASHION"."SHOP_FACTS";
Or use the SAP HANA Studio.
- DeltaMerge.png (43.99 KiB) Viewed 34110 times
