PouchDB indexing crashes cuase need to much memory on ios

Intro

I have build an IOS app with PouchDB and Ionic and Cordova stuff, but now i'm failing with the database and can't see a solution...

sqlite

Sqlite plugin and the synchronization works great, but as soon i want to access the data PouchDB starts indexing which uses to much memory and my app crashes.

WebSQL

In WebSQL I can't even sync the database, because I get the "QuotaExceededError" Error. Is there a way to ask for more space in an IOS uiwebview?

indexeddb

Indexedb isn't usable, cause of too many bugs. And will it also not be better in IOS 9

So any ideas ideas or hints?