Some "experts" in our organization claim that the original iSeries file structure - physical/logical file, is a "flat file". Is this true? Or is it somewhat considered a relational database?
The iSeries database originates from what existed on System/34 and 36. At the time, all files were flat. Even though you could build indexes, file facilities were very limited.
System/38 brought in a revolution. It introduced physical and logical files as we know them on iSeries. It brought the possibility to have fields described in files and automatically usable in programs.
SQL was then added, eventually enabling companies to have some files created in SQL, some others created through DDS while using traditional programming tools (such as RPG) and new ones (such as SQL) on either type.
With a further release, the iSeries database became truly relational thanks to the introduction of constraints and triggers.
On top of that, SQL carries on developing. You can now create files with blob, clob and so on.
Not so flat to me.
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