Re: RPG and Threads

Hi, Douglas:

See:
http://iprodeveloper.com/systems-management/optimizing-as400-batch-performance

for a good overview of how to approach this, especially the section on "Splitting Input into Multiple Jobs".

Also, how many records are you talking about in this large file? millions? billions? and how many fields (columns) per record? If there are many fields, you may be incurring a lot of (needless) overhead due to the way RPG processes file record data by default. As each row is read, RPG normally uses generated code to move each field from the record buffer position into a local variable of the same name, and so, if you are only summarizing a few columns, but there are many fields in each record, that extra overhead can quickly overwhelm the total processing time You can avoid that overhead by doing a READ into a data structure where the data structure layout is based on (matches) the file record layout.

Hope that helps,

Mark S. Waterbury

> On 6/1/2016 10:37 AM, Englander, Douglas wrote:

Does anyone have a simple program example (or know where I can find one) for an RPG program that creates thread jobs? I am wanting to know if it is possible for one RPG program (or CL) to start 4 or 5 threads, and each thread would process one part of a file, instead of having one program process the file from beginning to end. This is a read and summarize application that is being converted to SQL, but even with SQL, it takes a long (7+ hours) to process the whole file.