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. 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.






2. Command to get help docs on a specific command at the collection level.






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






4. Returns one document matching the optional properties.






5. Javascript code. Documents can contain code as values.






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






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






8. Returns help information for a command.






9. command to start the mongo shell.






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






11. In BSON - represents the smallest possible value.






12. Operator allowing the execution of arbitrary javascript as part of the selector.






13. command to start the mongo shell.






14. Contains query conditional used to check if a value contains the field value.






15. command to start the mongodb process.






16. Appends a value to field - if the field is an existing array. Otherwise it sets the field to the array [value] if field is not present. ex: { $push : { field : value } }






17. 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.






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






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






20. 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 ] } } }






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






22. 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.






23. Returns help information for a command.






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






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






26. ...






27. Operator allowing the partial specification of fields in an embedded document in an array.






28. command to start the mongodb process.






29. A document contained by a parent document. The embedded document is a value of a key in the parent document.






30. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.






31. 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.






32. Appends each value in the value_array to the field - if field is an existing array. Otherwise - it sets the field to the array value_array - if field is not present ex: { $pushAll : { field : value_array } }






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






34. Standard javascript regular expressions. These can be stored in documents






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






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






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






38. The standard number representation in the javascript shell.






39. 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 },






40. Meta query conditional used to negate the selector.






41. Binary-encoded serialization of mongo documents.






42. In BSON - represents the largest possible value.






43. 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 } }






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






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






46. Adds a document to a collection.






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






48. Adds a document to a collection.






49. Update a document in the collection.






50. 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"}});