Demonstrate the use of Map/Reduce technology to efficiently process data.

Question 1

In a Map/Reduce script, which entry function is the beginning of the script and is only invoked once?

Answer 1

getInputData

Question 2

In a Map/Reduce script, which entry function can be skipped if the Reduce entry point is present, and is invoked once for each key/value pair provided by getInputData?

Answer 2

Map

Question 3

In a Map/Reduce script, which entry point can be skipped if the map entry point is present, and is invoked once for each key/value pair provided by map or getInputData if map is not present

Answer 3

Reduce

Question 4

True or False?

In a Map/Reduce, the summarise function is optional, and only invoked once.

Answer 4

True

Question 5

What does the summaryContext.concurrency property show?

Answer 5

Shows the maximum concurrency number when running the map/reduce script.

Question 6

What does the summaryContext.dateCreated property show?

Answer 6

Shows the time and day when the script began running.

Question 7

What does the summaryContext.seconds property show?

Answer 7

Shows the total number of seconds that elapsed during the processing of the script.

Question 8

What does the summaryContext.usage property show?

Answer 8

Shows the total number of usage units consumed during the processing of the script.

Question 9

What does the summaryContext.yields property show?

Answer 9

Shows the total number of yields that occurred during the processing of the script.

Question 10

What does the summaryContext.inputSummary object contain?

Answer 10

Object that contains data about the input stage

Question 11

What does the summaryContext.inputSummary.dateCreated property contain?

Answer 11

The time and day when the getInputData(inputContext) function began running.

Question 12

What does the summaryContext.inputSummary.error property contain?

Answer 12

Holds serialized errors thrown from the getInputData(inputContext) function

Question 13

What does the summaryContext.inputSummary.seconds property contain?

Answer 13

The total number of seconds that elapsed during execution of the getInputData(inputContext) function. This tally does not include idle time.

Question 14

What does the summaryContext.inputSummary.usage property contain?

Answer 14

The total number of usage units consumed by processing of the getInputData(inputContext) function.

Question 15

What does the summaryContext.mapSummary object contain?

Answer 15

Contains data about the map stage

Question 16

What does the summaryContext.mapSummary.concurrency property contain?

Answer 16

The maximum concurrency number for executing parallel tasks during the map stage

Question 17

What does the summaryContext.reduceSummary.concurrency property contain?

Answer 17

The maximum concurrency number for executing parallel tasks during the reduce stage.

Question 18

What does the summaryContext.mapSummary.dateCreated property contain?

Answer 18

The time and day when the map function began running.

Question 19

What does the summaryContext.reduceSummary.dateCreated property contain?

Answer 19

The time and day when the reduce function began running.

Question 20

What does the summaryContext.mapSummary.errors property contain?

Answer 20

Holds all serialized errors thrown from the map function.

May also hold the SSS_APP_SERVER_RESTART error code, which is recorded in the event of an application server restart.

Question 21

What does the summaryContext.reduceSummary.errors property contain?

Answer 21

Holds all serialized errors thrown from the reduce function.

May also hold the SSS_APP_SERVER_RESTART error code, which is recorded in the event of an application server restart.

Question 22

What does the summaryContext.mapSummary.keys property contain?

Answer 22

Holds the keys that were passed to the map stage by the getInputData stage.

Note that keys are sorted in the following way:

If all values are numeric, values are listed in numeric order.
If one or more values are strings, values are listed in lexicographical order.

Question 23

What does the summaryContext.reduceSummary.keys property contain?

Answer 23

Holds the keys that were passed to the reduce stage, either by the map stage, if it was used, or by the getInputData stage.

These keys are listed in lexicographical order.

Question 24

What does the summaryContext.mapSummary.seconds property contain?

Answer 24

Total seconds elapsed when running map.

Question 25

What does the summaryContext.reduceSummary.seconds property contain?

Answer 25

Total seconds elapsed when running reduce.

Question 26

What does the summaryContext.mapSummary.usage property contain?

Answer 26

Total number of usage units consumed when running map.

Question 27

What does the summaryContext.reduceSummary.usage property contain?

Answer 27

Total number of usage units consumed when running reduce.

Question 28

What does the summaryContext.mapSummary.yields property contain?

Answer 28

Total number of times yields when running map.

Question 29

What does the summaryContext.reduceSummary.yields property contain?

Answer 29

Total number of times yields when running reduce.

Question 30

What does the summaryContext.output property contain?

Answer 30

Iterator that contains the keys and values saved as the output of the reduce stage.