persistent data feature, or sqlite3 feature?

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

People proposed the goal of giving Emacs the feature of persistent
objects.  For that goal, there is no particular reason to use a
general-purpose database package.

A general-purpose database package such as sqlite3 surely does not
come with a built-in representation for storing Lisp objects in
general.  Emacs would need to have a way to encode them as byte
sequences, and store those byte sequences in the database.
(This encoding might be `prin1' or it might be something else.)

It follows that sqlite3 databases containing persistent Lisp data
stored by Emacs will not in general be naturally interoperable with
sqlite3 databases made by other programs.  Other programs won't know
about this encoding.  If the other program is meant to be a general
tool, such as a database explorer, it could I suppose operate on Emacs
database files, but anything that really wants to understand its data
won't interoperate with Emacs.

It follows that there is no particular benefit from using a
general-purpose database system such as sqlite3 _for the purpose of holding
persistent Lisp data_.

People are also talking about wanting the feature of using Emacs to operate
on sqlite3 databases for various purposes.

That feature could be useful, but my point is _it's a different
feature_.

This discussion is switching between two different features,

1. Persistent objects.

2. Access to arbitrary sqlite3 databases.

and that makes it incoherent.

We could implement either feature.  We could implement both.
But one of them should not control the design of the other!

-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)