What is the difference between coalesce and repartition, as well as between cache and persist?

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Accepted Answer

Coalesce reduces the number of partitions without shuffling data, while repartition increases the number of partitions by shuffling data. Cache and persist are used to persist RDDs in memory.

Coalesce is used to reduce the number of partitions without shuffling data, while repartition is used to increase the number of partitions by shuffling data.
Coalesce is more efficient when reducing partitions as it avoids shuffling, while repartition involves shuffling data across the network.
Cache and persist are used to persist RDDs in memory to avoid recomputation, with cache storing data in memory by default and persist allowing for different storage levels like DISK_ONLY or MEMORY_AND_DISK.

What is the difference between coalesce and repartition, as well as between cache and persist?

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