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package simpledb;

/** A class to represent a fixed-width histogram over a single integer-based field.

*/

public class IntHistogram {

/**

* Create a new IntHistogram.

*

* This IntHistogram should maintain a histogram of integer values that it receives.

* It should split the histogram into "buckets" buckets.

*

* The values that are being histogrammed will be provided one-at-a-time through the "addValue()" function.

*

* Your implementation should use space and have execution time that are both

* constant with respect to the number of values being histogrammed. For example, you shouldn't

* simply store every value that you see in a sorted list.

*

* @param buckets The number of buckets to split the input value into.

* @param min The minimum integer value that will ever be passed to this class for histogramming

* @param max The maximum integer value that will ever be passed to this class for histogramming

*/

public IntHistogram(int buckets, int min, int max) {

// some code goes here

}

/**

* Add a value to the set of values that you are keeping a histogram of.

* @param v Value to add to the histogram

*/

public void addValue(int v) {

// some code goes here

}

/**

* Estimate the selectivity of a particular predicate and operand on this table.

*

* For example, if "op" is "GREATER_THAN" and "v" is 5,

* return your estimate of the fraction of elements that are greater than 5.

*

* @param op Operator

* @param v Value

* @return Predicted selectivity of this particular operator and value

*/

public double estimateSelectivity(Predicate.Op op, int v) {

// some code goes here

return -1.0;

}

/**

* @return

* the average selectivity of this histogram.

*

* This is not an indispensable method to implement the basic

* join optimization. It may be needed if you want to

* implement a more efficient optimization

* */

public double avgSelectivity()

{

// some code goes here

return 1.0;

}

/**

* @return A string describing this histogram, for debugging purposes

*/

public String toString() {

// some code goes here

return null;

}

}