[xxyzz]

I think I have figured out how to use the ion library and I'm investigating the kdf sqlite file now. And I have 4 questions so far:

- How fragment ids are created? Only section rows start from "c0", others start from a random id like the first anchor id is "a1B9".
- How eidbucket_* rows are created?
- The section rows always have an non-exists kfx_id field, for example here is the text ion data of the "c0" row in the fragments table:

$ion_1_0
section::{
  section_name: kfx_id::"c0",
  page_templates: [
    structure::{
      kfx_id: kfx_id::"i3",
      story_name: kfx_id::"l4",
      fixed_width: 1400,
      fixed_height: 2100,
      layout: scale_fit,
      float: center,
      type: container
    }
  ]
}

the "i3" fragment id doesn't exist
- The meaning of the numbers in section_position_id_map, for example, the "c117-spm" row:

$ion_1_0
section_position_id_map::{
  section_name: kfx_id::"c117",
  contains: [
    [
      1,
      kfx_id::"i11A"
    ],
    [
      2,
      kfx_id::"i11E"
    ],
    [
      3,
      kfx_id::"i11C"
    ],

I'm not sure what's 1, 2, 3.

I have attached the epub and the kdf files, I added a text ion table "text_fragments" to the db file. The book is downloaded from https://standardebooks.org.