Online DDL --analyze-table: use non-local ANALYZE TABLE

[shlomi-noach]

Description

Followup to #17201. In that PR we issue a ANALYZE NO_WRITE_TO_BINLOG TABLE on the shadow table just before cut-over, which brings statistics up-to-date and results in a more seamless transition as the shadow tabel takes the place of the original table.

However, if a failover (PRS/ERS) takes place shortly after the cut-over, then the promoted replica's statistics for the shadow table can be far off. Or, irrespective of failover, read queries on replicas can also suffer from a sub-optimal execution plan.

With this PR we issue a "normal" ANALYZE TABLE which is then replicated. This can cause an increase in replication lag at cut-over time, but it is generally expected to be low, as the shadow table is not yet used by any production traffic, hence is not under any concurrency and does not suffer from locking issues.

Related Issue(s)

• Online DDL: ANALYZE the shadow table before cut-over #17201
• Online DDL: shadow table can under-perform on cut-over due to poor statistics. Proposing to ANALYZE it before cut-over. #17200

Checklist

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 67.65%. Comparing base (b1f6147) to head (a30d776).

Files with missing lines	Patch %	Lines
go/vt/vttablet/onlineddl/executor.go	0.00%	3 Missing ⚠️
go/vt/vttablet/onlineddl/vrepl.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17462      +/-   ##
==========================================
- Coverage   67.66%   67.65%   -0.01%     
==========================================
  Files        1584     1584              
  Lines      254360   254362       +2     
==========================================
- Hits       172116   172098      -18     
- Misses      82244    82264      +20     

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[mattlord]

OK, so this is only called as part of the analyze step where it makes sense not to replicate it. Versus the cutover step where we continue (pre #7201) to use the replicated variant.

[shlomi-noach]

Correct!