I am trying to understand the Definitive Guide and would appreciate if someone can help me out clarifying my thoughts.

I would like to ask two questions.

[1]  In the book it says ,


> Elasticsearch added a translog, or transaction log, which records every operation in Elasticsearch as it happens. With the translog, the process now looks like this:

In the  [segment merging](https://www.elastic.co/guide/en/elasticsearch/guide/current/merge-process.html#merge-process)  process, is it first recorded in the translog and then data are flushed to the disk?

[2] If yes, is the number of _operations_ and _size of operation result_ for segment merging included in below  section for Node Stats API ?

        "translog" : {
          "operations" : 9245364,
          "size_in_bytes" : 10886196986