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How to Create a Table with Merge and partitions in HANA

Former Member
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Hi,

What is the best way to create a Table with MERGE and PARTITION and UNLOAD PRIORITIES.

Any body can you please give me some examples.

Regards,
Deva

Accepted Solutions (0)

Answers (1)

Answers (1)

lbreddemann
Active Contributor
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How about using the SAP HANA SQL reference guide to find the command syntax?

Besides: I suppose if the 'how' is not clear then likely the 'what', 'why' and 'when' are also not really clear.

So, why exactly do you want to create tables with specific unload priorities or merge clauses?

Are you aware of the implications?


- Lars

Former Member
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Hi Lars,

my requirement is ,

1.While loading  the data from ETL , i should be done based on the priority( means Load priority)

2. Once the data is maximu( >2GB) we need to unload the data.

3.Once the data is unloaded , we need to use some functions(like flush() in c ) to make it clean.

4.and partition the table base on the year(2009,2010,2011 and other) to improve the performance while creating table.

5.we need to merge to reduce the memory space.

All these should need to be define while creating table.

Thanks & Regards,

Deva

lbreddemann
Active Contributor
0 Kudos

Ok,

1) the UNLOAD PRIORITY has nothing to do with the order of data loads in your ETL process

2) Unloading of columns will happen automatically. Don't specify anything specific for the tables, then SAP HANA will take care about it

3) Not sure where you get your ideas from, but there is no need to manually "flush" tables or anything like that. SAP HANA will take care of memory housekeeping.

4) Partitioning and how to specify it for tables has been largely documented. Just read up on it.

5) Delta Merge will happen automatically, as long as you don't prevent it (e.g. by trying to outsmart the mergedog rules)

Seriously, I get the impressions that this list of requirements is based on some hear-say and lack of actual information and experience with SAP HANA. There are a couple of extensive discussions on data loading optimization available here in SCN and on SAPHANA.COM. Please read those first.

All this had been discussed broadly a couple of times.

- Lars