[Zope] ZODB vs SQL

[Johan Carlsson [EasyPublisher]]

At 11:04 2003-01-15 -0400, aborel said:
>In "Choosing to store data in SQL vs ZODB" located=20
>http://www.zope.org/Members/anthony/sql_vs_ZODB
>
>i read :
>"Will the data be frequently changing?
>
>If the data is going to be frequently changing, then it's not a good idea=
=20
>to put it in the ZODB.
>Every time the data changes, a new record will be appended to the Data.fs=
=20
>file - this could become a problem very quickly."
>
>Does that mean that the changes AND the old version of the object are kept=
=20
>in ZODB ?

Yes.


>If it's true, is packing a good way to throw away the old versions of the=
=20
>object ?

Yes.

>If Not, What are the good ways ?

You could also use a non-logging storage or some other more lightweight
storage. (The session data manager uses a RAM-based storage, which isn't
persistent over reboots, but works well as frequent writes, short time=20
storage.)

I also believe a non-logging storage is used for the Wikis on Zope.org.

If your going to have really high write frequency SQL probably the most
sensible choice. There are some really high-end database manager
available for you.

A SQL server could also sensible if you want to do queries (as available
through SQL (calculations, subqueries and that kind of thing).
This will most probably be faster than any special Python/ZCatalog
equivalent, at least for substantial amount of data (which RDBMs are=
 designed
to handle). ZODB/ZCatalog are not designed to do these things.

Hm.. That's a bit more information that you asked for ;-)
I think I better stop now ;-)

Cheers,
Johan Carlsson



--=20
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