7.10. Multidimensional Clustering Tables and Block Indexes
Multidimensional clustering (MDC), as its name implies, allows for clustering of the physical data pages in multiple dimensions. For example, using the sales table illustrated previously in Figure 7.15, you can cluster the data based on two dimensions: sales_person and year columns. This method of clustering has several benefits over clustering indexes.
With MDC, the data pages are physically clustered by several dimensions simultaneously. With clustering indexes, only one cluster index is allowed per table; the other indexes in the table are unclustered.
MDC guarantees clustering over time even though frequent INSERT operations are performed. Thus, less maintenance and overhead is required. ...
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