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  1. Core Server
  2. SERVER-57483

Results from $lookup stage are not cached for a resharding operation's sub-pipeline

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    • Backwards Compatibility:
      Fully Compatible
    • Operating System:
      ALL
    • Backport Requested:
      v5.0
    • Sprint:
      Sharding 2021-06-14
    • Story Points:
      1

      Description

      DocumentSourceLookUp::buildPipeline() calls ShardServerProcessInterface::attachCursorSourceToPipeline() which calls sharded_agg_helpers::attachCursorToPipeline() and always serializes and re-parses, even when the pipeline may execute locally on the shard via ShardServerProcessInterface::attachCursorSourceToPipelineForLocalRead().

      Because the $sequentialCache stage omits itself from the serialized pipeline, the parsed pipeline which executes locally on the shard won't ever use the cache.

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              Assignee:
              max.hirschhorn Max Hirschhorn
              Reporter:
              max.hirschhorn Max Hirschhorn
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                Updated:
                Resolved: