Update README.md

README.md

@@ -26,27 +26,36 @@ This dataset contains all posts submitted to StackOverflow before the 14th of Ju
 The dataset contains over 60 Million posts, totaling ~40GB in size and ~65 billion characters of text.<br>
 The data is sourced from [Internet Archive StackExchange Data Dump](https://archive.org/download/stackexchange).
 
-## Data Fields
+## Dataset Structure
+
+Each record corresponds to one post of a particular type.
+Original ordering from the data dump is not exactly preserved due to parallelism in the script used to process the data dump.
+The markdown content of each post is contained in the `Body` field. The license for a particular post is contained in the `ContentLicense` field.
+
+
+### Data Fields
 ```typescript
 {
   Id: long,
-  PostTypeId: long
-  AcceptedAnswerId: long | null,
-  ParentId: long | null,
+  PostTypeId: long, // 1=Question, 2=Answer, 3=Orphaned tag wiki, 4=Tag wiki excerpt, 5=Tag wiki, 6=Moderator nomination, 7=Wiki Placeholder, 8=Privilige Wiki
+  AcceptedAnswerId: long | null, // only present if PostTypeId=1
+  ParentId: long | null, // only present if PostTypeId=2
   Score: long,
   ViewCount: long | null,
   Body: string | null,
-  Title: string | null
+  Title: string | null,
   ContentLicense: string | null,
   FavoriteCount: long | null,
   CreationDate: string | null,
   LastActivityDate: string | null,
   LastEditDate: string | null,
   LastEditorUserId: long | null,
-  OwnerUserId: long | null
+  OwnerUserId: long | null,
   Tags: array<string> | null
 }
 ```
+Also see ![Datadump Database Schema Documentation](https://meta.stackexchange.com/questions/2677/database-schema-documentation-for-the-public-data-dump-and-sede), as all fields
+have analogs in the original dump format.
 
 ## How to use?
 
@@ -142,9 +151,12 @@ The value `field` of a `TextNode` contains the free standing text without any fu
   - For each element of `element.select("th")`
     - `${element.text()} | `
   - After the loop `\n| ` is emitted
-  - `--- | ` is emitted exactly as many times as the number of `<th>` children previously iterated over.
+  - For each element of `element.select("th")`
+    - For each character of the `th.text()`
+      - `-` is emitted
+    - After the loop over each character of th ` | ` is emitted
   - `\n` is emitted
-  - For each element of `element.select("tr")`
+  - For each element of `element.select("tr")` with more than one children of tag type `td`
     - `| ` is emitted
     - For each element of `element.select("td")`
       - `${td.text()} | ` is emitted