Hi, By task, I mean http://code.google.com/appengine/docs/java/taskqueue/overview.html
About transactionnality of your changes: you have to make sure that when you delete, it's gauranteed to be recreated. The only way to do so is to start a task bound to the transaction where you delete. See http://code.google.com/appengine/docs/java/taskqueue/overview.html#Tasks_within_Transactions You can go the way 1 entity only per entity group (i.e then no entity group per se) but then it means that you lose the transactionnality service of GAE: i.e no way to guarantee that your changes are done all at once or not at all. It's very important to keep transactionnality if you want to guarantee integrity of your data on the long run. For transactions, read http://code.google.com/appengine/docs/java/datastore/transactions.html regards didier On Dec 6, 2:34 pm, asianCoolz <[email protected]> wrote: > how about, if i denormalized everything . Mean book as id of > subcategory. One entitygroup will only has one entity. any impact on > that if i have too many separate entitygroups...? is this good > practice in bigtable? if i do aware if i do this way, not be able to > use transactional. > > can you elaborate > > "The best (only ?) way to continue > guaranteeing integrity of your data in to do it via a task for the > second action (recreate) that you make transactional with the 1st > (delete). " -- do you mean i should re-created book in subcategoryB > first before do delete book from subcategoryA ? what do you mean > "task", using background job ? any example? -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
