一些通过SAP ABAP代码审查得出的ABAP编程最佳实践

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因为需用用ABAP OPEN SQL读取一张涵盖海量记录的数据库表,那末推荐使用OPEN CURSOR进行分块读取。

3. If the file is regarding IPG or MIDH or TPG, handle with each line separately

2. The more number of ZINSERT call, the better performance will be gained by using parallel

Loop at all service BOM, check whether the ID in current loop does exist in validation table lt_valid_prod or lt_valid_sp. If so, delete them via DELETE TABLE XXX FROM .

It is an expensive operation to open a file in application server with 50MB file size.

Although this solution will spend almost the same time to fetch the data from DB, it has far less memory consumption compared with using SELECT to fetch ALL data from DB at one time.

你这个 办法 和直接用SELECT相比,能显著减少内存消耗量。

1. The more CPU & DB time spent in ZINSERT, the better performance will be gained by using

Improvement: use DELETE XXX WHERE product_id NOT IN . It is more efficient when lt_srv_bom_file has a huge number of records. See comparison below ( unit: second )

parallel processing (Asynchronous RFC call).

processing.

你这个 函数里执行一大堆计算,怎么让 把传入的product ID写到一张自定义表ZJERRY1里。

注意第二种方案使用STARTING NEW TASK达到的并发执行效果:

这是八个性能现象报告 。使用ABAP原生支持的NOT IN关键字还需用获得更好的性能。性能评测如下:

调用你这个 函数的代码:

1. 你这个 个IF ELSE分支里检测的条件着实逻辑上来说时会同一类,应该合并到八个IF分支里进行检查:

The correct logic should be:

2. Handle with each line directly without evaluate file path in the BIG loop.

通过比较,第二种正确处理方案的速率单位单位 是第你这个 的四倍。

通过下面这段代码模拟八个费时的ABAP应用程序:

定义八个ABAP函数:

The original dump due to out of memory issue could be eliminated by replace SELECT with OPEN CURSOR statement.

In product / IObject area, the best practice is to use OPEN CURSOR / FETCH NEXT CURSOR to access big DB table.

2. Read the file content line by line

1. Check the file path whether it is IPG or MIDH or TPG related. If not, quit the report.

1. Open the file in application server

Current logic is: