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Former Member
Jul 06, 2010 at 12:17 PM

Query on memory consumption during SQL

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Hi SAP Gurus,

Could I kindly request for your inputs concerning the following scenario?

To put it quite simply, we have a program where we're required to retrieve all the fields from a lengthy custom table, i.e. the select statement uses an asterisk. Unfortunately, there isn't really a way to avoid this short of a total overhaul of the code, so we had to settle with this (for now).

The program retrieves from the database table using a where clause filtering only to a single value company code. Kindly note that company code is not the only key in the table. In order to help with the memory consumption, the original developer had employed retrieval by packages (also note that the total length of each record is 1803...).

The problem encountered is as follows:

- Using company code A, retrieving for 700k entries in packages of 277, the program ran without any issues.

- However, using company code B, retrieving for 1.8m in packages of 277, the program encountered a TSV_TNEW_PAGE_ALLOC_FAILED short dump. This error is encountered at the very first time the program goes through the select statement, ergo it has not even been able to pass through any additional internal table processing yet.

About the only biggest difference between the two company codes is the number of corresponding records they have in the table. I've checked if company code B had more values in its columns than company code A. However, they're just the same.

What I do not quite understand is why memory consumption changed just by changing the company code in the selection. I thought that the memory consumed by both company codes should be the same... at least, in the beginning, considering that we're retrieving by packages, so we're not trying to get all of the records all at once. However, the fact that it failed at the very beginning has shown me that I'm gravely mistaken.

Could someone please enlighten me on how memory is consumed during database retrieval?

Thanks!