release-21.2: colbuilder: fall back to row-by-row processor wrapping for many renders

[yuzefovich]

Backport 2/2 commits from #85822.

/cc @cockroachdb/release

---

colbuilder: add a microbenchmark for running many render expressions

This commit adds a microbenchmark of queries with many render
expressions. It'll be used in the following commit to tune when we fall
back to wrapping a row-by-row processor to handle those renders.

Release note: None

colbuilder: fall back to row-by-row processor wrapping for many renders

This commit introduces a mechanism to handle render expressions by
wrapping a row-by-row processor into the vectorized flow when

1. the estimated number of rows to go through the renders is relatively
   small
2. the number of renders is relatively high.

The idea is that the vectorized projection operators have higher
overhead when many of them are planned AND there is not enough data to
amortize the overhead, so to improve the performance in those cases
we'll use the row-by-row noop processor. Both of the thresholds are
controlled by cluster settings and the defaults were chosen based on
a representative microbenchmark.

It's worth pointing out that we only have the estimated row count for
the scan operators, so the change has limited applicability.

RenderPlanning/rows=1/renders=1-24           407µs ± 2%     408µs ± 2%     ~     (p=0.684 n=10+10)
RenderPlanning/rows=1/renders=8-24           516µs ± 1%     537µs ± 1%   +4.05%  (p=0.000 n=10+10)
RenderPlanning/rows=1/renders=32-24          832µs ± 1%     811µs ± 1%   -2.59%  (p=0.000 n=10+10)
RenderPlanning/rows=1/renders=64-24         1.22ms ± 0%    1.14ms ± 1%   -6.62%  (p=0.000 n=9+10)
RenderPlanning/rows=1/renders=128-24        2.02ms ± 0%    1.80ms ± 1%  -11.18%  (p=0.000 n=8+9)
RenderPlanning/rows=1/renders=512-24        7.75ms ± 1%    5.75ms ± 1%  -25.77%  (p=0.000 n=10+9)
RenderPlanning/rows=1/renders=4096-24        160ms ± 1%      62ms ± 1%  -61.51%  (p=0.000 n=10+9)
RenderPlanning/rows=4/renders=1-24           438µs ± 2%     438µs ± 1%     ~     (p=0.853 n=10+10)
RenderPlanning/rows=4/renders=8-24           603µs ± 1%     633µs ± 2%   +5.06%  (p=0.000 n=10+10)
RenderPlanning/rows=4/renders=32-24         1.08ms ± 1%    1.08ms ± 1%     ~     (p=0.105 n=10+10)
RenderPlanning/rows=4/renders=64-24         1.72ms ± 0%    1.62ms ± 0%   -5.83%  (p=0.000 n=9+9)
RenderPlanning/rows=4/renders=128-24        3.01ms ± 1%    2.75ms ± 1%   -8.78%  (p=0.000 n=10+10)
RenderPlanning/rows=4/renders=512-24        11.6ms ± 1%     9.6ms ± 2%  -17.58%  (p=0.000 n=10+10)
RenderPlanning/rows=4/renders=4096-24        192ms ± 2%      91ms ± 2%  -52.58%  (p=0.000 n=10+10)
RenderPlanning/rows=16/renders=1-24          494µs ± 1%     499µs ± 1%   +1.03%  (p=0.006 n=10+8)
RenderPlanning/rows=16/renders=8-24          855µs ± 1%     901µs ± 1%   +5.37%  (p=0.000 n=10+10)
RenderPlanning/rows=16/renders=32-24        2.03ms ± 1%    2.04ms ± 1%     ~     (p=0.190 n=10+10)
RenderPlanning/rows=16/renders=64-24        3.58ms ± 1%    3.42ms ± 1%   -4.56%  (p=0.000 n=10+9)
RenderPlanning/rows=16/renders=128-24       6.74ms ± 1%    6.31ms ± 1%   -6.37%  (p=0.000 n=10+10)
RenderPlanning/rows=16/renders=512-24       26.9ms ± 1%    24.7ms ± 1%   -8.24%  (p=0.000 n=9+10)
RenderPlanning/rows=16/renders=4096-24       329ms ± 2%     218ms ± 2%  -33.66%  (p=0.000 n=10+10)
RenderPlanning/rows=64/renders=1-24          666µs ± 1%     659µs ± 2%   -1.07%  (p=0.007 n=10+10)
RenderPlanning/rows=64/renders=8-24         1.79ms ± 1%    1.84ms ± 1%   +3.01%  (p=0.000 n=10+10)
RenderPlanning/rows=64/renders=32-24        5.53ms ± 1%    5.79ms ± 2%   +4.74%  (p=0.000 n=10+10)
RenderPlanning/rows=64/renders=64-24        10.8ms ± 1%    11.0ms ± 1%   +1.87%  (p=0.000 n=10+9)
RenderPlanning/rows=64/renders=128-24       21.2ms ± 1%    21.7ms ± 1%   +2.71%  (p=0.000 n=10+10)
RenderPlanning/rows=64/renders=512-24       83.6ms ± 0%    84.9ms ± 0%   +1.47%  (p=0.000 n=10+7)
RenderPlanning/rows=64/renders=4096-24       824ms ± 1%     751ms ± 2%   -8.88%  (p=0.000 n=10+10)
RenderPlanning/rows=128/renders=1-24         853µs ± 1%     851µs ± 1%     ~     (p=0.481 n=10+10)
RenderPlanning/rows=128/renders=8-24        2.98ms ± 1%    3.11ms ± 1%   +4.32%  (p=0.000 n=10+10)
RenderPlanning/rows=128/renders=32-24       10.4ms ± 1%    10.9ms ± 1%   +5.44%  (p=0.000 n=10+10)
RenderPlanning/rows=128/renders=64-24       20.1ms ± 1%    21.3ms ± 1%   +5.99%  (p=0.000 n=10+10)
RenderPlanning/rows=128/renders=128-24      39.7ms ± 1%    42.1ms ± 2%   +5.98%  (p=0.000 n=10+10)
RenderPlanning/rows=128/renders=512-24       160ms ± 1%     168ms ± 2%   +5.13%  (p=0.000 n=9+10)
RenderPlanning/rows=128/renders=4096-24      1.44s ± 1%     1.48s ± 2%   +3.15%  (p=0.000 n=9+10)
RenderPlanning/rows=256/renders=1-24        1.22ms ± 1%    1.21ms ± 1%   -1.01%  (p=0.000 n=10+10)
RenderPlanning/rows=256/renders=8-24        5.22ms ± 0%    5.19ms ± 1%   -0.54%  (p=0.011 n=8+9)
RenderPlanning/rows=256/renders=32-24       19.9ms ± 1%    20.0ms ± 1%     ~     (p=0.182 n=9+10)
RenderPlanning/rows=256/renders=64-24       39.0ms ± 0%    38.9ms ± 0%   -0.33%  (p=0.023 n=10+10)
RenderPlanning/rows=256/renders=128-24      76.8ms ± 1%    76.7ms ± 1%     ~     (p=0.739 n=10+10)
RenderPlanning/rows=256/renders=512-24       316ms ± 1%     319ms ± 1%   +1.15%  (p=0.001 n=9+10)
RenderPlanning/rows=256/renders=4096-24      2.75s ± 1%     2.73s ± 1%   -0.64%  (p=0.002 n=8+9)

Fixes: #85632.

Release note: None

Release justification: performance regression fix.

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Patches should only be created for serious issues or test-only changes.
• Patches should not break backwards-compatibility.
• Patches should change as little code as possible.
• Patches should not change on-disk formats or node communication protocols.
• Patches should not add new functionality.
• Patches must not add, edit, or otherwise modify cluster versions; or add version gates.

If some of the basic criteria cannot be satisfied, ensure that the exceptional criteria are satisfied within.

• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
• The new functionality is additive-only and only runs for clusters which have specifically “opted in” to it (e.g. by a cluster setting).
• New code is protected by a conditional check that is trivial to verify and ensures that it only runs for opt-in clusters.
• The PM and TL on the team that owns the changed code have signed off that the change obeys the above rules.

Add a brief release justification to the body of your PR to justify this backport.

Some other things to consider:

• What did we do to ensure that a user that doesn’t know & care about this backport, has no idea that it happened?
• Will this work in a cluster of mixed patch versions? Did we test that?
• If a user upgrades a patch version, uses this feature, and then downgrades, what happens?

[cockroach-teamcity]

This change is 

[DrewKimball]

Reviewable status: complete! 1 of 0 LGTMs obtained