[Info-vax] CRTL and RMS vs SSIO

[Lawrence D’Oliveiro]

On Thursday, October 7, 2021 at 2:25:59 PM UTC+13, tink... at gmail.com wrote:

> All disks are block based, even on Unix.

The difference being, on *nix systems, the responsibility for blocking and deblocking is left to the filesystem layer. So if a file is n bytes long, and n mod «sector size» ≠ 0, the application never sees what is in the padding bytes, if any.

Some filesystems even implement “tail packing”, which means the leftover bits of multiple files can share the same block, all transparently to the application, minimizing fragmentation.

By the way, Linus Torvalds did apparently use a VMS system at some point. (Must have been after his Sinclair QL days.) Guess what reason he gave, when asked why he hated it ...

> RMS ISAM with fixed length records is a pain, I have long argued ISAM should support
>variable length records ...

Given that nowadays an SQL-based RDBMS like SQLite can offer full support for transactions, joins and subqueries (missing only more multi-user-type features like locking and replication), and yet still be resource-light enough to fit in your mobile phone, I would say the time for application developers to be grubbing about in ISAM files is past.