alternatingblock

An alternatingblock is a term used in data organization to describe a sequence of blocks in which a defining property alternates between two states from one block to the next. In its simplest form the blocks alternate type, such as data blocks of type A and type B (A, B, A, B, …). The alternation can be controlled by a binary flag or by a scheduling rule, and it may be enforced across a file, stream, or memory region.

Definition and structure: An alternatingblock consists of a contiguous sequence of blocks with a fixed period of two. The pattern can be extended to more complex cycles (A, B, A, B, … or A1, A2, A1, A2, …). The concept emphasizes locality and predictable layout, which can aid in prefetching, caching, and parallel processing. It can also be used to separate data and parity or to distinguish tiers of storage.

Implementation: Common implementations store a per-block indicator (bit) that marks the block type and a higher-level controller that enforces the alternating rule. Robust implementations may include validation checks to detect violations and trigger recovery.

Applications: In storage systems, alternating blocks can support quick parity checks or error detection by alternating data and parity blocks. In streaming and video encoding, alternating blocks can separate frames or macroblocks to simplify processing. In interleaving and memory hierarchy design, alternation can improve bandwidth utilization.

See also: block, interleaving, data stripe, parity block, error-correcting code, tiling.