To answer this question, we need to understand the concept of CISZ (Clustered Index Scan Zone) and its relationship with random and sequential processing.
A CISZ is a continuous block of data within a clustered index that can be read efficiently during a scan operation. The size of the CISZ is determined by the fill factor, which is the percentage of space used in a data page.
Let's go through each statement to determine which one is true:
Statement (1) - A smaller CISZ results in faster retrieval for random processing at the expense of inserts.
This statement is true. A smaller CISZ means that more data pages need to be accessed during random processing, resulting in faster retrieval. However, smaller CISZ also means that more data pages need to be split and inserted when new data is added, which can slow down inserts.
Statement (2) - A larger CISZ is less efficient for sequential processing.
This statement is false. A larger CISZ is more efficient for sequential processing because it allows for larger data reads, reducing the number of I/O operations required. Sequential processing involves reading data in a continuous manner, and a larger CISZ can accommodate larger data blocks, improving performance.
Statement (3) - A larger CISZ is less efficient for random processing.
This statement is false. A larger CISZ can actually be more efficient for random processing. With a larger CISZ, more data can be read in a single I/O operation, reducing the number of disk accesses required for random retrieval.
Statement (4) - A smaller CISZ results in slower retrieval for sequential processing at the expense of inserts.
This statement is false. A smaller CISZ can actually result in faster retrieval for sequential processing. Sequential processing involves reading data in a continuous manner, and a smaller CISZ means that fewer data pages need to be accessed, reducing the I/O operations required.
Based on the explanations above, the correct statement is (1) - A smaller CISZ results in faster retrieval for random processing at the expense of inserts.