Database schema:
CREATE TABLE Document_Subsets (
  Document_Subset_ID NUMBER PRIMARY KEY,
  Document_Subset_Name TEXT,
  Document_Subset_Details TEXT
);
CREATE TABLE Collection_Subsets (
  Collection_Subset_ID NUMBER PRIMARY KEY,
  Collection_Subset_Name TEXT,
  Collecrtion_Subset_Details TEXT
);
CREATE TABLE Document_Objects (
  Document_Object_ID NUMBER PRIMARY KEY,
  Parent_Document_Object_ID NUMBER,
  Owner TEXT,
  Description TEXT,
  Other_Details TEXT
);
CREATE TABLE Collections (
  Collection_ID NUMBER PRIMARY KEY,
  Parent_Collection_ID NUMBER,
  Collection_Name TEXT,
  Collection_Description TEXT
);
CREATE TABLE Documents_in_Collections (
  Document_Object_ID NUMBER PRIMARY KEY,
  Collection_ID NUMBER,
  FOREIGN KEY (Collection_ID) REFERENCES Collections(Collection_ID),
  FOREIGN KEY (Document_Object_ID) REFERENCES Document_Objects(Document_Object_ID)
);
CREATE TABLE Document_Subset_Members (
  Document_Object_ID NUMBER PRIMARY KEY,
  Related_Document_Object_ID NUMBER,
  Document_Subset_ID NUMBER,
  FOREIGN KEY (Document_Subset_ID) REFERENCES Document_Subsets(Document_Subset_ID),
  FOREIGN KEY (Related_Document_Object_ID) REFERENCES Document_Objects(Document_Object_ID),
  FOREIGN KEY (Document_Object_ID) REFERENCES Document_Objects(Document_Object_ID)
);
CREATE TABLE Collection_Subset_Members (
  Collection_ID NUMBER PRIMARY KEY,
  Related_Collection_ID NUMBER,
  Collection_Subset_ID NUMBER,
  FOREIGN KEY (Collection_Subset_ID) REFERENCES Collection_Subsets(Collection_Subset_ID),
  FOREIGN KEY (Related_Collection_ID) REFERENCES Collections(Collection_ID),
  FOREIGN KEY (Collection_ID) REFERENCES Collections(Collection_ID)
);

Question: Which document has least number of related documents? List the document id and the number of related documents.
SQL: SELECT Document_Object_ID , count(*) FROM Document_Subset_Members GROUP BY Document_Object_ID ORDER BY count(*) ASC LIMIT 1;

Question: How many collections does each document belong to? List the count and the document id.
SQL: SELECT count(*) ,  T2.Document_Object_ID FROM Collections AS T1 JOIN Documents_in_Collections AS T2 ON T1.Collection_ID = T2.Collection_ID GROUP BY T2.Document_Object_ID

Question: What are the owners of the document objects described as the 'Braeden Collection'?
SQL: SELECT OWNER FROM Document_Objects WHERE Description  =  'Braeden Collection'

Question: Which collection is not the parent of other collection? List the collection's name.
SQL: SELECT Collection_Name FROM Collections EXCEPT SELECT T2.Collection_Name FROM Collections AS T1 JOIN Collections AS T2 ON T1.Parent_Collection_ID = T2.Collection_ID;

Question: what are the collection names?
SQL: SELECT Collection_Name FROM Collections;

Question: For each document object id, how many children do they have?
SQL: SELECT T2.Document_Object_ID ,  count(*) FROM Document_Objects AS T1 JOIN Document_Objects AS T2 ON T1.Parent_Document_Object_ID = T2.Document_Object_ID GROUP BY T2.Document_Object_ID ORDER BY count(*) DESC LIMIT 1;

Question: Who is the owner of the parent document of every documents where 'Marlin' is the owner?
SQL: SELECT T2.Owner FROM Document_Objects AS T1 JOIN Document_Objects AS T2 ON T1.Parent_Document_Object_ID = T2.Document_Object_ID WHERE T1.Owner  =  'Marlin'

Question: What is the description of collection named Best?
SQL: SELECT Collection_Description FROM Collections WHERE Collection_Name = "Best";

Question: What are the different subset names of all documents owned by Braeden?
SQL: SELECT DISTINCT T1.Document_Subset_Name FROM Document_Subsets AS T1 JOIN Document_Subset_Members AS T2 ON T1.Document_Subset_ID =  T2.Document_Subset_ID JOIN Document_Objects AS T3 ON T2.Document_Object_ID  =  T3.Document_Object_ID WHERE T3.owner  =  'Braeden'

Question: How many child collection does the collection named Best has?
SQL: SELECT count(*) FROM Collections AS T1 JOIN Collections AS T2 ON T1.Parent_Collection_ID = T2.Collection_ID WHERE T2.Collection_Name = "Best";

Question: What is the number of child collections belonging to the collection named Best?
SQL: SELECT count(*) FROM Collections AS T1 JOIN Collections AS T2 ON T1.Parent_Collection_ID = T2.Collection_ID WHERE T2.Collection_Name = "Best";

Question: What are the collection susbset names?
SQL: SELECT Collection_Subset_Name FROM Collection_Subsets;

Question: What is the document object id with the least number of documents ?
SQL: select document_object_id , count(*) from document_subset_members group by document_object_id order by count(*) asc limit 1;

Question: For the document subset named 'Best for 2000', what are the document ids in that subset?
SQL: SELECT DISTINCT T1.Document_Object_ID FROM Document_Subset_Members AS T1 JOIN Document_Subsets AS T2 ON T1.Document_Subset_ID =  T2.Document_Subset_ID WHERE T2.Document_Subset_Name = "Best for 2000";

Question: How many different collections are related to the one named 'Best'?
SQL: SELECT count(DISTINCT T1.Related_Collection_ID) FROM Collection_Subset_Members AS T1 JOIN Collections AS T2 ON T1.Collection_ID  =  T2.Collection_ID WHERE T2.Collection_Name = "Best";

Question: What are the different subsets of documents related to each document id , list the name of the document subset and id of the actual document ?
SQL: select distinct t3.document_subset_name ,  t1.document_object_id from document_subset_members as t1 join document_subset_members  as t2 on t1.related_document_object_id = t2.document_object_id join document_subsets as t3 on t2.document_subset_id =  t3.document_subset_id

Question: What is the count of documents owned by Marlin?
SQL: SELECT count(*) FROM Document_Objects WHERE OWNER = "Marlin";

Question: Which unique subset does document owned by Braeden belong to? List the subset name.
SQL: SELECT DISTINCT T1.Document_Subset_Name FROM Document_Subsets AS T1 JOIN Document_Subset_Members AS T2 ON T1.Document_Subset_ID =  T2.Document_Subset_ID JOIN Document_Objects AS T3 ON T2.Document_Object_ID  =  T3.Document_Object_ID WHERE T3.owner  =  'Braeden'

Question: How many child documents does each parent document has? List the document id and the number.
SQL: SELECT T2.Document_Object_ID ,  count(*) FROM Document_Objects AS T1 JOIN Document_Objects AS T2 ON T1.Parent_Document_Object_ID = T2.Document_Object_ID GROUP BY T2.Document_Object_ID;

Question: List all document which is related to document owned by Ransom . List the document id .
SQL: select t1.document_object_id from document_subset_members as t1 join document_objects as t2 on t1.document_object_id  =  t2.document_object_id where t2.owner  =  'ransom'

Question: What are the different document ids that are in the subset named 'Best for 2000' or in the collection named 'Best'?
SQL: SELECT DISTINCT T1.Document_Object_ID FROM Document_Subset_Members AS T1 JOIN Document_Subsets AS T2 ON T1.Document_Subset_ID =  T2.Document_Subset_ID JOIN Documents_in_Collections AS T3 ON T1.Document_Object_ID  =  T3.Document_Object_ID JOIN Collections AS T4 ON T3.Collection_ID  =  T4.Collection_ID WHERE T2.Document_Subset_Name = "Best for 2000" OR T4.Collection_Name = "Best";

Question: List id of documents that in document subset Best for 2000 and collection named Best.
SQL: SELECT DISTINCT T1.Document_Object_ID FROM Document_Subset_Members AS T1 JOIN Document_Subsets AS T2 ON T1.Document_Subset_ID =  T2.Document_Subset_ID JOIN Documents_in_Collections AS T3 ON T1.Document_Object_ID  =  T3.Document_Object_ID JOIN Collections AS T4 ON T3.Collection_ID  =  T4.Collection_ID WHERE T2.Document_Subset_Name = "Best for 2000" AND T4.Collection_Name = "Best";

Question: List collection subset id, name and number of collections in each subset.
SQL: SELECT T2.Collection_Subset_ID ,  T1.Collection_Subset_Name ,  count(*) FROM Collection_Subsets AS T1 JOIN Collection_Subset_Members AS T2 ON T1.Collection_Subset_ID =  T2.Collection_Subset_ID GROUP BY T2.Collection_Subset_ID;