Why results from a simple search and a batch search can be slightly different?

If you search "Shakespeare" in the search bar and if you run a query containing "Shakespeare" in a batch search, you can get slightly different documents between the two results.

Why?

For technical reasons, Datashare processes both queries in 2 different ways:

a. Search bar (a simple search processed in the browser):

The search query sent to Elasticsearch is processed in your browser by Datashare's client. It is then sent to Elasticsearch through Datashare server which forwards your query.

b. Batch search (several searches processed by the server):

1. Datashare's server processes each of the batch search's queries 2. Each query is sent to Elasticsearch. The results are saved into a database 3. When the batch search is finished, you get the results from Datashare 4. Datashare sends back the results stored into the database/ Datashare's team attempts to make both results be similar, but slight differences can happen between the two queries.