How to push out tables from memory in SAP HANA 1.0 SP11

[mandeep_kauldhar]

How to push out tables from memory in SAP ECC6 EHP7 based HANA 1.0 SP11?

I have ECC6 ehp7 based upon SAP HANA DB 1.0 sp11; the DB system shows currently used memory 130 gb. We are only using Plant Maintenance module so most of the buffered tables we won’t be using.

I already tried few option

• Set parameter reload_tables to false in SQL section
• In the indexserver.ini file by adding the parameter tablepreload_write_interval in the persistence section

I know there is a table where we can set value for each column or row table to load table data into memory to reduce memory usage. I tried table TABLES but there is no entry with TRUE or true.

Any reply is appreciated.

Mani

[mandeep_kauldhar · Accepted solution]

Thank you all for information.

Yes i want to unload unused Column store tables after every HANA DB restart as well as during normal operation also. by default SAP load tons of SAP tables which will not be used in my case; i want to find them and unload them manually or set flag to not load them.

I know we can load and unload but where do i find all the tables loaded into memory along with their memory occupied information? is there any table which stores this information so i can unload memory expensive tables manually or using SQL script?

Mani

[former_member229826 · Accepted solution]

Hi Mani,

You can use below SQL to find the top 200 column store table details. You can change the number of tables by changing the value 200.

Note: Ensure "Maximum number of rows displayed in Result" is more than 200 in your hana studio. It can be changed as mentioned below.

Hana Studio - Menu --> Windows --> Preferences -->

Search string: Result

Regards,

Nalla

[yakcinar]

Hello Mandeep,

HANA loads all row-based tables into memory. You cannot avoid this.

Most of the tables are columnar-based and these tables and their columns could be loaded into memory partially.

You can load and unload table or columns individually using either HANA Studio context menu or SQL Scrripts as colleagues mentioned.

In addition to this, you can have detailed info about memory consumption of a table by opening Table Definition from context menu and going to the Runtime Information tab. There is a "Loaded" field for all columns of a table on Runtime Information tab and below "Details for table" page and "Columns" tab. You can see below picture.

May be you can make these field values to False for some tables. Most prorbably SAP is making all these loaded property of a table to "True". Not sure whether you can change them manually.

Regards,

Yuksel AKCINAR

[sivakumar_kilari3]

Hi,

You can release tables from memory.

Select the table by right click and choose the option “Unload

Thanks

siva

[Former Member]

you can use sql command to unload/load tables from memory.

unload <table_name>

load <table_name>

or you can also perform this from studio in system view.

please refer to the Hana admin guide for more details. (help.sap.com/hana)

if you are having performance issue then you may need to investigate the issue in detail rather than unloading the table from memory.

[former_member229826]

Hi,

Are you looking to unload unused Column store tables after every HANA DB restart?

Regards,

Nalla