Hi
Dne Fri, 05 Jun 2009 05:32:02 -0400
Marc Delisle <marc(a)infomarc.info> napsal(a):
Yes there are downsides for each alternative. Another
downside for the
EAV model is that at user login (session initialization) we need to read
all the rows holding the user prefs for this user, instead of just one
read if each option has its own column.
With index on login name, selecting several rows should be quite cheap.
As mentionned in one of the links I gave, the EAV
model also makes it
difficult to code the possible choices for an option, for example into
an ENUM.
Okay, I probably can live with either of solutions. Both have downsides
and advantages.
About upgrading, I expect Zeeshan to implement a
feature to auto-create
and auto-upgrade the table (which could be extended to all of our pmadb
tables).
It should be coded with this in mind.
--
Michal Čihař |
http://cihar.com |
http://blog.cihar.com