Hi,
shall we now go ahead and make SQLite the default DB for GRASS 6.3+?
Hamish
The main thing I'm concerned about SQLite support is that I think by default it stuffs all tables for all vector layers in a mapset into a single DB file.
I think you can connect to different DB files before creating vectors, thus separating them, but it would be nice to have something more automatic, like what happens with DBF files. Say a subfolder for SQLite DBs, and connect to the folder, new vectors get their own SQLite DB file generated automatically in that folder.
Maybe a bit confusing since you would have 'database' meaning the folder and 'database' meaning the SQLite files in that folder,
A few problems with a single DB file:
- It could get HUGE. I'm not worried so much about file system limits, but it's a possibility.
- easy for corruption in the DB file to make all vectors in the mapset useless.
- backups. You can't backup a single vector, since you would be backing up the attribute data for all vectors in the process. And incremental backups would be longer (especially if it's huge) - if a single small vector changed (attributes) in a mapset, you still need to backup the attribute DB for all vectors.
On Aug 23, 2006, at 8:19 AM, Hamish wrote:
Hi,
shall we now go ahead and make SQLite the default DB for GRASS 6.3+?
Hamish
-----
William Kyngesburye <kyngchaos@kyngchaos.com>
http://www.kyngchaos.com/
"History is an illusion caused by the passage of time, and time is an illusion caused by the passage of history."
- Hitchhiker's Guide to the Galaxy
On Thu, 2006-08-24 at 01:19 +1200, Hamish wrote:
shall we now go ahead and make SQLite the default DB for GRASS 6.3+?
Hamish,
I do have some concern over SQLite's performance under large data sets.
SQLite was not designed for data mining, but as a lightweight DBMS and
middleware for others, IIRC.
However, SQLite is quite easy to use. I don't see a big problem making
it the default since it's simple switch to another. Anyone else?
--
Brad Douglas <rez touchofmadness com> KB8UYR
Address: 37.493,-121.924 / WGS84 National Map Corps #TNMC-3785