AngularFire list is loaded every time i open the page

Ionic Framework
1

When I load a list (for example user) it works very well however, every time I load this famous page, the whole list is reloaded by firebase is so uses a lot of data …

How to load it only once during the session?

I have already tried to load the list once at the opening of the page in the TS but it still loads the data because of the ngIf in HTML …

<ion-col col-12>

    <p>Pseudo : {{user.p}}</p>

</ion-col>


this.users = await this.database.list( `G/${this.myUid}/U/` ).valueChanges().take(1);

I wish that when I open the page it loads the list the first time but when I close this page and I return later (in the same session) it does not reload the data but only that it me them posters