Test your basic knowledge |

Mongo Db

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Operator allowing the execution of arbitrary javascript as part of the selector.
$not
$where
$set
db.getLastError()

2. Returns all the documents matching the optional properties.
db.<collection>.insert({document});
$unset
db.<collection>.find([properties]);
$in

3. Copies an entire database from one name on one server to another name on another server. Omit frmHostName to copy from one name to another on the same server.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
db.<collection>.insert({document});
$pullAll
$or

4. Update call that inserts a new document if no update match is found. Allows the same code to be used for inserts as well as updates.
Upsert
show collections
$push
use <database name>

5. Clone the current database (implied by 'db') from another host.
binary data
boolean
db.myCollection.ensureIndex({keypattern},[{options}])
db.cloneDatabase(fromhost)

6. Returns help information for a command.
db.commandHelp("commandName")
BSON
use <database name>
$not

7. Command to get help docs on a specific command at the collection level.
string
$nin
db.<col>.help([commandName]);
mongo

8. command to start the mongo shell.
$lt
db.<collection>.findOne([properties]);
mongo
$lte

9. Command to get help docs on a specific command at the db level.
$pop
db.help([commandName]);
$mod
$lte

10. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
mongo
$set
db.<collection>.find([properties]);
$slice

11. In BSON - represents the smallest possible value.
mongo
minimum value
$set
Multi-updates

12. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});
$ne
$unset
embedded document
Multi-updates

13. command to start the mongodb process.
db.<collection>.insert({document});
$gt
$inc
mongod

14. Adds a document to a collection.
db.<collection>.insert({document});
$all
batch insert
db.<collection>.find([properties]);

15. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
db.<collection>.find([properties]);
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
64-Bit Integer
db.<collection>.find([properties]);

16. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
db.help([commandName]);
$not
db.getLastError()
64-bit floating point numbers

17. Update a document in the collection.
db.<col>.update({selector},{document});
db.<collection>.insert({document});
32-Bit Integer
$unset

18. Data structure used to store all other data in mongo databases.
mongo
db.cloneDatabase(fromhost)
Object.bsonsize({document});
document

19. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
$elemMatch
db.myCollection.ensureIndex({keypattern},[{options}])
$size
$gt

20. set of UTF-8 characters.
mongo
string
show collections
$or

21. Unique 12-byte ID for documents.
mongo
object id
$all
BSON

22. Adds a document to a collection.
db.<collection>.insert({document});
db.cloneDatabase(fromhost)
array
$pull

23. Returns all the documents matching the optional properties.
db.<col>.update({selector},{document});
code
db.<collection>.find([properties]);
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);

24. Update modifier that set the value of a key and if the key does not exist, it will create the key. ex: db.<col>.update({selector},{"$set":{"someKey":"someValue"}});
$gt
$set
mongo
db.cloneDatabase(fromhost)

25. Flushes all pending writes to data files. The lock option allows one to safely snapshot the database's data files. The async option returns focus to the console immediately while the task runs in the background.
$not
db.runCommand({fsync:1,lock:1,async:1})
$gt
db.<col>.remove({selector});

26. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
mongod
$not
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$pull

27. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
$
$gte
32-Bit Integer
regular expression

28. Positional operator that holds the position of the first matched array item in the query. Used to find an array member and then manipulate it. ex: {$inc:{'comments.$.votes':1}} where comments looks like: "comments" : [ { "by" : "joe", "votes" : 3 },
Cursor
$
key.index
mongod

29. changes the database on which you are working.
use <database name>
maximum value
$size
regular expression

30. Binary-encoded serialization of mongo documents.
BSON
$not
$lt
Upsert

31. Meta query conditional used to negate the selector.
db.cloneDatabase(fromhost)
$rename
$
$not

32. Clone the current database (implied by 'db') from another host.
$nin
db.myCollection.ensureIndex({keypattern},[{options}])
db.cloneDatabase(fromhost)
maximum value

33. Updates all matching documents, not just the first, that match the selector.
Multi-updates
regular expression
db.runCommand({fsync:1,lock:1,async:1})
use <database name>

34. Meta query conditional generating a modulus with the selector operand. Checks to see if the field value when divided by one value has the remainder of the second value.
db.<col>.update({selector},{document});
$mod
$pullAll
mongo

35. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}
$inc
$gte
$gt
$ne

36. Used to describe a variable as not having been initialized.
boolean
use <database name>
db.commandHelp("commandName")
undefined

37. A document contained by a parent document. The embedded document is a value of a key in the parent document.
string
$pop
binary data
embedded document

38. ...
batch insert
mongod
db.commandHelp("commandName")
$ne

39. String of arbitrary bytes.
mongod
binary data
Update Modifiers
db.myCollection.ensureIndex({keypattern},[{options}])

40. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
mongod
$rename
db.cloneDatabase(fromhost)
Cursor

41. Standard binary data type.
array
mongod
boolean
64-bit floating point numbers

42. In BSON - represents the largest possible value.
$gt
document
null
maximum value

43. Query conditional allowing the selector to choose between more than one optional criteria.
$in
$ne
$or
Update Modifiers

44. command to start the mongodb process.
embedded document
mongod
$size
$inc

45. Stored as milliseconds since the epoch.
db.<collection>.find([properties]);
db.cloneDatabase(fromhost)
date
maximum value

46. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
Cursor
db.<collection>.insert({document});
db.<collection>.find([properties]);
$lt

47. Command to list commands and descriptions of those commands in the context of the database.
db.commandHelp("commandName")
help
use <database name>
db.<collection>.insert({document});

48. Operator allowing the partial specification of fields in an embedded document in an array.
$rename
help
$elemMatch
$all

49. Set or list of values.
array
binary data
code
Cursor

50. Contains query conditional used to check if a value contains the field value.
$in
show collections
$inc
Multi-updates