Ionic storage needs 1GB of space


I am using ionic storage in my app and It needs almost 1GB device space to launch the app.
If device memory is not having at least 1GB of space app will not be launched. After clearing that memory I am able to launch.

Please help me to solve this issue. I am new in ionic
I am using
ionic framework : 3.9.2
Ionic App scripts: 3.1.2
Angular Core: 5.0.0