[Zope] General information

Michel Pelletier michel@digicool.com
Tue, 27 Apr 1999 11:43:20 -0400


> 
> With ZTables (a non open source Zope product) you can do more 
> relational
> database stuff inside the Zope database; I don't yet have enough
> experience with it to give solid commentary, but from what 
> I've seen it
> certainly is very nice.
>  

I've seen some talk on the list last week about ZTables, but I didn't
have the chance to jump in and give our angle on what ZTables actually
is.  There seems to be the impression that Ztables is a realtional
(like) database product, but this isn't really what ZTables is about.
Since there are rumors (they're even rumors here, every now and then we
hear paul and rob talking about things when they're coming to unchain us
at 8pm from our desks) about some sort of open soucing of ZTables, I
thought I'd give you all a breakdown on what it is, from my perspective.

Zope 1.10.2 came with our indexing machinery "Below the Line" (meaning
Open Source).  The indexing stuff is really low level (can be only used
in python) and faily straightforward.

An index is basicly a fast way of searching through some mass of data.

Over the past few years we've developed a product that uses the indexing
stuff.  Originally called DataPublisher, then Tabula, and now ZTables.

ZTables allows a Zope manager to create, extend, maintain and publish
tabular like data.  "tabular like data" is defined as various columns
(which define the schema) and any number of rows of data that fit that
schema.  A simple tabular like example is:

id		meta_type		title
one		'Folder'		''
two		'DTML Method'	'Hi my name is Joe'
three		'User Folder'	'User Folder'

The columns are 'id', 'meta_type' and 'title' and there are three rows.
This is all quite simple really, but ZTables gives you some unique
abilities to do things with this tabular data.

First, ZTables manages the schema.  So new columns can be added or
deleted.

Ztables also manages indexes for all columns (columns can also not have
an index).  So searching through the data is very fast.

ZTables can construct "imaginary" colums which are computed when they
are accessed.  These are called Computed Fields.

ZTables gives you a Folder like management interface so you can add
search forms, report forms, and other stuff right in the ZTable.
ZTables also generates the fairly complex DTML reports and (potentialy)
lengthly HTML forms for you.

ZTables give you Hierarchies, to give you a more 'relational' feel to
you data.  There are also keyword hierarchies.

ZTables lets you merge seperate subcollections into the ZTable, so you
can bring various data sources into one sensible location.

ZTables gives you the ability to upload and import various database
flavors, including DBase, Rand, and comma delimited.

We are working now on bringing some kind of ZTables 'core' into Open
Source.  Details cannot be revealed at the moment.  This will be in
conjunction with a release of some form of 'Catalog'.  In fact, as it is
now, our Catalog Product is just a wrapper around ZTables.

-Michel