What is the performance wise difference between logical file & open query? When is it best to use open query and...
By submitting your email address, you agree to receive emails regarding relevant topic offers from TechTarget and its partners. You can withdraw your consent at any time. Contact TechTarget at 275 Grove Street, Newton, MA.
when to best to use logical file?
In many ways, reading through a logical file & OPNQRYF perform about the same. OPNQRYF extends beyond the capabilities of doing I/O through a logical file by providing the ability to do dynamic record selection, mapped fields, dynamic join, record aggregation, and other database functions.
If you're just starting to explore the use of the OPNQRYF statement, then it might also be a good time to look at embedding SQL statements in your RPG programs to perform dynamic selection, join, aggregation, etc. This recommendation is based on the fact that SQL is strategic interface for database access on iSeries servers.
MORE INFORMATION ON THIS TOPIC
Search400.com's targeted search engine: Get relevant information on DB2/400.
The Best Web Links: tips, tutorials and more.
Check out this online event, Getting the Most out of SQL & DB2 UDB for the iSeries.
Dig Deeper on DB2 UDB (universal databases)
Related Q&A from Kent Milligan
To monitor members stuck within a physical file on AS/400, you can periodically use the display file description (DSPFD) command to create an output ...continue reading
When developing tables in a parent-child relationship, use a primary key and a foreign key along with a unique ID to make your database easier to ...continue reading
IBM did not change the default of the reuse deleted files function to YES for physical files in order to minimize the impact on any existing ...continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.