Store big size tables with BLOB on disk instead of in memory in SAP HANA

[former_member347166]

Dear all,

is it possible to avoid loading of some big sized tables with BLOB data to memory in SAP HANA for ABAP based application? E.g. a big amount of images / scanned documents (>1T) as attachments to trancactional data and just access these attachmens on demand (line-by-line).

I've found some information where similar approach seems to be used: co-innovation project with Springer Science+Business Media (~3.8 Million rows (296 GB in memory / 4 TB on disk).

Thanks in advance for your response.

Alexander

[lbreddemann · Accepted solution]

Hello Alexander,

LOBS are handled separately during access.

As of SPS 7 you can decide whether a LOB should be stored within the tables storage containers or whether each lob should have its own storage container that can independently loaded to memory upon request.

In fact you can set a threshold keeping smaller LOBs in a shared container and have the extra handling only active for larger ones.

See ALTER TABLE - SQL Reference - SAP Library for more details on that.

By setting the threshold you can easily control when LOBs are loaded to memory.

- Lars

[former_member347166 · Accepted solution]

Hello Lars,

Thank you for your answer! It sounds really good for me.

So in our case (from the ABAP application) we can execute the ALTER TABLE statement via ADBC?

The threshold size is then valid for each particular LOB in the column?

I suppose the parameter cannot be set by the definition of the table in ABAP, only via ALTER TABLE statement?

Thank you and best regards,

Alexander

[lbreddemann · Accepted solution]

To be honest: I don't know if this parameter is already part of the ABAP DDIC.

- Lars