Avoid small batches in Exchange #12010
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Summary: Prevent exchange client from unblocking to early. Unblocking to early impedes effectiveness of page merging. When the cost of creating a vector is high (for example for data sets with high number of columns) creating small pages can make queries significantly less efficient. For example it was observed that when network is congested and Exchange buffers are not filled up as fast query may experience CPU efficiency drop up to 4x: T211034421 Differential Revision: D67615570
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Summary: X-link: facebookincubator/velox#12010 Prevent exchange client from unblocking to early. Unblocking to early impedes effectiveness of page merging. When the cost of creating a vector is high (for example for data sets with high number of columns) creating small pages can make queries significantly less efficient. For example it was observed that when network is congested and Exchange buffers are not filled up as fast query may experience CPU efficiency drop up to 4x: T211034421 Differential Revision: D67615570
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Summary:
Prevent exchange client from unblocking to early. Unblocking to early impedes
effectiveness of page merging. When the cost of creating a vector is high (for
example for data sets with high number of columns) creating small pages can
make queries significantly less efficient.
For example it was observed that when network is congested and Exchange buffers
are not filled up as fast query may experience CPU efficiency drop up to 4x: T211034421
Differential Revision: D67615570