The database commonly uses an index range scan to access selective data. The selectivity is the percentage of rows in the table that the query selects, with 0 meaning no rows and 1 meaning all rows. Selectivity is tied to a query predicate, such as WHERE last_name LIKE 'A%', or a combination of predicates.
Types of Distribution: Intensive, Selective and Exclusive Distribution. Some of the important types of distribution in international market are 1. Intensive 2. Selective and 3. Exclusive distribution.
There are a few different types of probability sampling: 1  Simple random sampling is, as the name suggests, the simplest type of probability sampling. 2  Stratified random sampling involves separating the population into subgroups and then taking a simple random sample from each of these subgroups.