The dystonias are movement disorders in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The movements, which are involuntary and sometimes painful, may affect a single muscle; a group of muscles such as those in the arms, legs, or neck; or the entire body.
Definition of Data Clustering. Data Clustering is the classification of a data set into a group of numbers, where members of each group surround a particular number.efinition of Data Clustering. Data Clustering is the classification of a data set into a group of numbers, where members of each group surround a particular number.
A clustered table is a table that is part of a cluster. A cluster is a group of tables that share the same data blocks because they share common columns and are often used together. Clusters and clustered tables are discussed in Chapter 18, Managing Clusters.