Test your basic knowledge |

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. changes the database on which you are working.






2. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.






3. Deletes a given field. ex: { $unset : { field : 1} }






4. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});






5. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});






6. The standard number representation in the javascript shell.






7. Lists all the collections in the database in use.






8. Not supported by the javascript shell and are converted to 64-bit floating point numbers.






9. set of UTF-8 characters.






10. Data structure used to store all other data in mongo databases.






11. Special keys passed in an update call to specify complex update operations - such as alter - adding - or removing keys - and even manipulating arrays and embedded documents.






12. Used to represent both a null value and a nonexistent field.






13. Adds a document to a collection.






14. In BSON - represents the largest possible value.






15. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.






16. Unique 12-byte ID for documents.






17. 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 },






18. Deletes documents from the collection based on the selector.






19. Query conditional allowing the selector to choose between more than one optional criteria.






20. Updates all matching documents, not just the first, that match the selector.






21. Standard binary data type.






22. Command to get help docs on a specific command at the db level.






23. Adds a document to a collection.






24. Deletes documents from the collection based on the selector.






25. Removes an element from an array based on the value of the field option being 1 or -1 for last or first element respectively. ex: { $pop : { field : -1 } }






26. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});






27. command to start the mongo shell.






28. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }






29. Returns the size of a document after it is converted to BSON from the JSON-like original.






30. 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.






31. 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.






32. Array specific conditional allowing matching on multiple elements within an array. The operation is non strict on the sequence of the values in the passed selector array.






33. 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.






34. Stored as milliseconds since the epoch.






35. Greater than query conditional. ex: db.<col>.find({numVal: {$gt:3}});






36. Used to describe a variable as not having been initialized.






37. Adds a value to the array only if its not in the array already. Otherwise, if the field is not present, it sets the field to the array value. ex: { $addToSet : { a : { $each : [ 3 , 5 , 6 ] } } }






38. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.






39. 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.






40. Does not contain query conditional used to select documents with the field that is not in the selector list of values.






41. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}






42. ...






43. Clone the current database (implied by 'db') from another host.






44. Returns all the documents matching the optional properties.






45. Clone the current database (implied by 'db') from another host.






46. command to start the mongodb process.






47. Syntax used for selectors to be specific to a certain element position within an array.






48. Array specific conditional used to select based on the length or set-size of an array field value.






49. Binary-encoded serialization of mongo documents.






50. Returns help information for a command.