Why should you run an SAP HANA delta merge? (2)

Question

Options

• ATo move most recent data from disk to memory
• BTo improve the read performance of InfoProviders
• CTo clear the BW query cache
• DTo decrease memory consumption

• A
  6% (3)
• B
  90% (43)
• C
  4% (2)

Explanation

Running a delta merge moves data from SAP HANA's write-optimized Delta Store (row-based, in memory) into the read-optimized Main Store (columnar, compressed). Once data is consolidated in the Main Store, analytical queries against InfoProviders run significantly faster (B), because HANA no longer needs to scan both stores and merge results at query time. Additionally, the Main Store applies dictionary encoding and compression, so the same data occupies less memory than it did in the Delta Store (D).

Why the distractors are wrong:

• A is wrong because both the Delta Store and Main Store already reside in memory - delta merge is a reorganization within memory, not a disk-to-memory load operation.
• C is wrong because clearing the BW query cache is a completely separate administrative action with no connection to HANA's internal storage merge process.

Memory tip: Think of delta merge as "compacting and organizing your filing cabinet" - it doesn't bring new files in (not A), it doesn't clear a whiteboard (not C), but it does make finding files faster (B) and frees up drawer space (D).

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