Display logical file as400

AS to IBM i. A join logical file can only have one record format. We cannot delete, update and write records to the physical file using the join logical file i.

We cannot use commitment control with the Join logical file JLF. The first file in JLF is the primary file and all other files would be secondary files. Try to keep the file having the most number of records as the primary file in the JLF for the performance per se.

Now when you process using DYNSLT, it will read all the records in the file, but do the selection of which records to process at that time rather than having done all the maintenance ahead of time. Difference between access path and Dynamic select. Dynamic select occurs whenever the program reads file. But access path occurs before the file is read but not necessarily. Record formats being defined. Field-level entries optional. Key field —level entries optional. Entries in join logical file:. Select and Omit field level entries.

There must one primary file and can have more than I secondary files. The format for this keyword is:. Inner join means the matching records in between the joining file will be selected.

Left outer join all the records from primary file and matching records from the secondary file will be selected. A physical file can be joined to itself to read records that are formed by combining two or more records from the PF itself. Non join logical file. Join logical file. We can able to insert or delete or update records using non-logical file. Insertion, updating or deletion of records is not possible in join logical files. For an example, let's make up a query to show the items ordered by a customer:.

For that, a DDS spec is still the best. This will help if you are trying to an order by on your view, but will not really help if you have a performance issue. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Can i create "logical files" in AS using sql? Ask Question. Asked 10 years, 11 months ago. Active 9 years, 10 months ago.

Viewed 11k times. I need to create as "logical files". Is it possible to create "logical files" with sql statements? If yes I would appreciate a sample statement. Improve this question. Aba Dov Aba Dov 4 4 gold badges 12 12 silver badges 20 20 bronze badges. Tracy Probst Hi, My original purpose was to create a materialized query containing a select on multiple tables for performance. I think you may be a bit stuck on the nomenclature here.

The "as" now called IBM i operating system describes files in one of two basic ways. Either a physical or a logical file. An SQL Table is like a physical. Indexes and Views are like logicals.