Final answer:
In a logical index, pointers are replaced with bitmapped values, which provide a more efficient way to perform searches and retrieve data in databases.
Step-by-step explanation:
In a logical index, pointers to table blocks are replaced with bitmapped values. Logical indexing in databases uses a map or array of bits to represent the presence or absence of an element rather than storing actual pointers. This makes searches faster and more efficient as operations can be performed at the bit level using bitwise operators.
A common example is a bitmap index, which is frequently used in database management systems to speed up the retrieval of data. To create boolean arrays with elements that meet predetermined criteria, apply conditions to arrays. This process creates logical arrays.
Use Indexing with Logical Arrays: These boolean arrays can be used as indices to choose elements from other arrays. The logical array's 'true' places are matched by elements.
Without explicitly iterating through the array, logical indexing allows for the quick and easy selection of array members that satisfy specific requirements. By filtering, subsetting, or removing particular items based on logical requirements, this technique improves array-based data processing and manipulation.