Which host is data stored in Extended tables when using Dynamic Tiering?

[former_member202764]

I was going over the SAP HANA academy videos and it mentions that the installation process asks for a location for data/log volumes in the HANA server host and it shows the default location as /hana/data_es/<SID> and /hana/log_es/<SID> in the HANA Server itself and that this location should only be accessible to the Dynamic Tiering Host. My understanding is that this location has to be on the Dynamic Tiering Host. Is my understanding correct or am I missing something?

Request you to elaborate on this.

Thanks in advance.

[muthuram_shanmugavel2 · Accepted solution]

Hi Sheel,

Please check this link.

SAP HANA Dynamic Tiering Setup | SCN

You will get idea

Regards,

Muthuram

[former_member202764 · Accepted solution]

Thanks for the response. But like I said, the question is not about how to do it. It is about the discrepancy that I seek a clarity on. The /hana/data_es/<SID> is the folder structure on the HANA server host. This I assume is the place where all the warm data gets stored. But in theory according to the demos, the warm data gets stored in the dynamic tiering host. This is where the confusion is.

[muthuram_shanmugavel2 · Accepted solution]

Hi Sheel,

Dynamic Tiering is 2 Node (Host) system.

In Host 1, HANA DB will be Installed

In Host 2, Dynamic Tiering (Sybase IQ DB) will be Installed.

Data Volumes,

1. /hana/data/HDT
2. /hana/data_es/HDT

are shared storage and can be accessible from Both the Nodes.

If we generally look, The Confusion might arise that

Both the folder structure are accessible from HANA servers,

Both are HANA DB Hard Disks. Where is My Warm Data will store.

I will explain this.

Creating  Column Table:

Creating Column Table and loading the data, Data will be stored in In-Memory.

Hard Disc - hana/data/HDT - will be used for Persistent Storage during "Save Point".

Data have been Unloaded from In-memory.

If you retrieve this data, The data will be loaded from Hard Disc to RAM and will occupy the RAM Memory and again you have to do Unloading.

Creating  Column Table USING EXTENDED STORAGE:

CREATE TABLE "SHANMUGAVEL".t2

(A INT, B INT NULL, C INT NOT NULL) USING EXTENDED STORAGE

If we load the data to this Table, It won't be stored in RAM and

directly Data will be stored in Dynamic Tiering Storage - /hana/data_es/HDT.

This Data will be manageable by Sybase IQ DB.

If you retrieve this data, Data won't store and occupy RAM Memory.

--------------------------------------------------------------------------------------------------------------------------------------

Though  /hana/data_es/<SID> is the folder structure on the HANA server host,

It will be used during extended Storage and managed by IQ DB in different host.

hana/data/HDT will be used for save point operation.

Regards,

Muthuram

[former_member202764 · Accepted solution]

Thanks Muthuram

That helps.

Regards,

Sheel