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Questions about generating hash tables

  • 1.  Questions about generating hash tables

    Posted 02-19-2019 00:21

    When the system generates a hash table.In shard table join, if fragment_num is greater than 1, mapd will compute shard_count = 0. Why not use real shard_count, is that a bug or an intentional design? According to the code logic, this will use all the data to make a hash table on a single card, not by sharding.



  • 2.  RE: Questions about generating hash tables

    Posted 02-19-2019 00:57

    Where is the code you’re talking about? I think the intention there is to limit each shard to one fragment to simplify the code – it should always be possible to create a number of shards which guarantees that.