<p>I would like to wipe out all data for a specific kind in Google App Engine. What is the
best way to do this?
I wrote a delete script (hack), but since there is so much data is
timeout's out after a few hundred records. </p>

Presumably your hack was something like this:
```
```
# Deleting all messages older than "earliest_date"
q = db.GqlQuery("SELECT * FROM Message WHERE create_date < :1", earliest_date)
results = q.fetch(1000)

while results:
    db.delete(results)
    results = q.fetch(1000, len(results))
```
```
As you say, if there's sufficient data, you're going to hit the request timeout before it gets through all the records. You'd have to re-invoke this request multiple times from outside to ensure all the data was erased; easy enough to do, but hardly ideal.
The admin console doesn't seem to offer any help, as (from my own experience with it), it seems to only allow entities of a given type to be listed and then deleted on a page-by-page basis.
When testing, I've had to purge my database on startup to get rid of existing data.
I would infer from this that Google operates on the principle that disk is cheap, and so data is typically orphaned (indexes to redundant data replaced), rather than deleted. Given there's a fixed amount of data available to each app at the moment (0.5 GB), that's not much help for non-Google App Engine users.