Details
Description
SQLBinary.hashCode() and SQLChar.hashCode() use a very simple algorithm that just takes the sum of the values in the array. This gives a poor distribution of hash values because similar values will have a higher probability of mapping to the same hash code, and the higher bits won't be used unless the array is very long. We should change these methods so that they use an algorithm similar to the one used in java.lang.String.hashCode(), described here: <URL:http://java.sun.com/javase/6/docs/api/java/lang/String.html#hashCode()>. This may have a positive effect on the performance of hash scans as it will reduce the likelihood of collisions in the hash table.