Google App Engine - Search API index growth -

i know how can estimate growth (how size increasez in period of time) of index of app engine search api (fts) based on number of entities inserted , amount of information. know how index size calculated (on depend). specifically:

1. when inserting new entities, growth (size) influenced number of previous existing entities? (ie. growth exponential)? ex. if have 1000 entities , insert 10, index grow x bytes. if have 100000 entities , insert 10, increase x or more x (exponentially, let' 10*x) ?
2. does number of fields (properties) influences size exponentially? ex. if have entity 2 fields , entity b 4 fields (let's identical in values, mathematical simplicity) size increase, when adding entity b, twice of entity or more that?
3. what other means can use find statistical information; have other tools in cloud console of app engine, or can programmatically ?

thank you.

you can check size of given index running code below.

from google.appengine.api import search  index in search.get_indexes(fetch_schema=true):     logging.info("index %s", index.storage_usage) # pseudo code amount_of_items_to_add = 100 x = 0 x <= amount_of_items_to_add:     search_api_insert_insert(data)     x+=1 #rerun loop see how size increased index in search.get_indexes(fetch_schema=true):     logging.info("index %s", index.storage_usage) 

this code not complete working example, should able build simple method takes data inserts search api , returns how used storage increased.