How could I predefine my schemas in the parse server cloud side?

@Moumouls Thanks for kind help.
Actually I met the problem described in this post:

I think maybe the simple solution is to create the unique indexes on the related fields, which should be “restrictive mode”, otherwise that bug still will happen.

BTW, we have already used the indexes in our schemas similar as below, but it looks like NOT unique index?

indexes: {
    tagsIndex: { tags: 1 },
    // The special prefix _p_ is used to create indexes on pointer fields
    cityPointerIndex: { _p_city: 1 },
    tagAndCityIndex: { _p_city: 1, tags: 1 },
  },

Any further help is highly appreciated.

Best regards, Jason