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Author's profile photo Nicholas Chang

Simple query comparison between SAP In-Memory CS with disk storage SAP Dynamic Tiering

Hi All,

Just to share the result for simple queries performed on in memory Column Store table with SAP Dynamic Tiering Extende table on disk storage.


HANA DB Version – HANA SPS09 revision 91

SAP Dynamic Tiering – SAP IQ 16 SP9


a) RLV (delta) enable on Extended Storage

b) Number of entries for CS table and ES table is identical as data in ES table was copied from CS table.

-> Column Store

-> Extended Storage

Simple queries performed and its results:

From the result above, we see that complete search (select *) is faster for Extended Storage and queries with selection process is much faster on CS.

This probably Extended Storage is ROW-BASED storage as per for visualize plan below? Remote Row Scan is used all queries on Extended Storage table.

Trying to figure out more how exactly Dynamic Tiering works for its Extended Table especially during data insert/import, unfortunately, couldn’t dig more as there’s no useful info written on esserver trace, indexserver trace, etc, and also log files in SAP IQ directories.

What I can see is just the size growing on file system, HANA admin cockpit and view M_ES_*

Input for this missing technical piece on SAP Dynamic Tiering Extended Table is greatly welcomed and appreciated.

Nicholas Chang

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      Author's profile photo Lars Breddemann
      Lars Breddemann

      As mentioned in your other blog post, ESS is not row based - but the communication between indexserver and ES server is. That's why you see a "row scan" operation.

      It doesn't tell you exactly what's happening in the ES server, but rather shows you how the indexserver "sees" the operation.

      Compare that to the SDA table acesses - it's pretty similar in this regard.

      - Lars

      Author's profile photo Nicholas Chang
      Nicholas Chang
      Blog Post Author

      Hi Lars,

      Thanks for the precious answers as always.. btw, i think i need more time to digest.

      Thanks again!

      Nicholas Chang