tustvold opened a new pull request, #4522:
URL: https://github.com/apache/arrow-datafusion/pull/4522
# Which issue does this PR close?
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Closes #.
# Rationale for this change
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The existing memory manager interface is quite tricky to use, and has
resulted in the proliferation of "utility" wrappers to make it easier to work
with. It also mixes the concept of limiting memory, with "memory scheduling"
where it tries to distribute memory "fairly". In practice I'm not sure this
would have worked, and would likely have blocked tokio worker threads #4325.
This PR proposes a drastic simplification of MemoryManager
# What changes are included in this PR?
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There are a couple of major changes worth highlighting:
* MemoryManager will no longer block waiting for capacity
* MemoryManager no longer attempts to guarantee any form of "fairness",
memory policy can be handled at a higher level by creating separate memory
pools for queries to execute from
* ExternalSorter will refuse to sort batches that are larger than it can
allocate from the memory pool
# Are these changes tested?
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# Are there any user-facing changes?
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