release-22.1: opt: add setting to always use histograms to calculate stats

[rytaft]

Backport 1/1 commits from #98194.

/cc @cockroachdb/release

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Informs #64570

Release note (sql change): Added a new session setting, optimizer_always_use_histograms, which ensures that the optimizer always uses histograms when available to calculate the statistics of every plan that it explores. Enabling this setting can prevent the optimizer from choosing a suboptimal index when statistics for a table are stale.

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Release justification: low-risk stats improvement gated by a disabled session setting

[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]

Reviewed 10 of 10 files at r1, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @michae2 and @rytaft)

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pkg/sql/opt/memo/memo.go line 75 at r1 (raw file):

// equivalence by simple pointer comparison. For example:
//
//	SELECT * FROM a, b WHERE a.x = b.x

Looks like some formatting got changed during the backport.

[rytaft]

TFTR!

Reviewable status: complete! 0 of 0 LGTMs obtained (and 1 stale) (waiting on @DrewKimball and @michae2)

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pkg/sql/opt/memo/memo.go line 75 at r1 (raw file):

Previously, DrewKimball (Drew Kimball) wrote…

Looks like some formatting got changed during the backport.

Done.

[michae2]

Reviewed 8 of 10 files at r1, 2 of 2 files at r2, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (and 1 stale) (waiting on @DrewKimball)