Stack Exchange - Data Explorer

Tables / ERD

The, imho, most important tables and attributes are depicted in the following graphic (drawn with draw.io):

postType

There are 8 post types

id	name
1	Question
2	Answer
3	Wiki
4	TagWikiExcerpt
5	TagWiki
6	ModeratorNomination
7	WikiPlaceholder
8	PrivilegeWiki

voteTypes

There are 14 vote types

id	name
1	AcceptedByOriginator
2	UpMod
3	DownMod
4	Offensive
5	Favorite
6	Close
7	Reopen
8	BountyStart
9	BountyClose
10	Deletion
11	Undeletion
12	Spam
15	ModeratorReview
16	ApproveEditSuggestion

tagSynonyms

The following SQL statement returns no records. Thus, the attribute sourceTagName is shown to be unique:

select
   count(*)  cnt,
   sourceTagName
from
   tagSynonyms
group by
   sourceTagName
having
   count(*) > 1

Github repository data-stackexchange, path: /erd/analysis/tagSynonyms-uniqueSourceTagName.sql

Both, sourceTagName and targetTagName are found in the tags table. As of 2019-03-19, the table tagSynonyms had 4437 records of which 1387 could be joined to tagSynonyms via sourceTagName and 4365 via targetTagName.

select
   count(syn.id) cntSynonyms,
   count(tag.id) cntFoundSourceTagNames
from
   tagSynonyms syn                                     left join
   tags        tag on syn.sourceTagname = tag.tagName

Github repository data-stackexchange, path: /erd/analysis/tagSynonyms-joinSourceTagName.sql

select
   count(syn.id) cntSynonyms,
   count(tag.id) cntFoundTargetTagNames
from
   tagSynonyms syn                                     left join
   tags        tag on syn.targetTagname = tag.tagName

Github repository data-stackexchange, path: /erd/analysis/tagSynonyms-joinTargetTagName.sql

Other queries

Most Upvoted Questions: The top 20 questions with the most up-votes (ignores down-votes)

Most Upvoted Answers: The top 20 answers with the most up-votes (ignores down-votes)

10 Words Likely To Get Post Closed as Non-Constructive - Too Slow because it has a method to split the words in the title.

find 10 words which, in titles, are most likely to cause a question to be closed as Not Constructive seems to try a similar thing.

Interesting queries on Data Explorer collected some interesting queries on meta.stackexchange.com.

Data dumps

Dumps of the stackexchange databases can be downloaded from archive.org/download/stackexchange.