schemadiff: temporal range partition rotation analysis and operation

[shlomi-noach]

Description

This PR introduces elaborate analysis and operations over temporal range partitioned tables.

Temporal range partitioned tables are tables with range partitions using any form of temporal value, ie:

• Using PARTITION BY RANGE COLUMNS (col_name) over a single column of type DATE or DATETIME
• Using PARTITION BY RANGE (temporal_func(col_name)) using one of several explicitly supported functions:
  • TO_SECONDS
  • TO_DAYS
  • YEAR
  • In 8.4: UNIX_TIMESTAMP and using a TIMESTAMP column

schemadiff then offers:

• AnalyzeTemporalRangePartitioning() returning TemporalRangePartitioningAnalysis, which determines whether the table is at all partitioned by RANGE, and can be considered as being temporal partitioned. Analysis includes the minimal rotation interval, the function used, if any, the column used, whether MAXVALUE is used, etc.
• TemporalRangePartitioningNextRotation(), given a table, interval, expected ahead-of-time partitions and time reference, returning a list of ALTER TABLE statements that prepare futuristic empty partitions, as needed. schemadiff analyzes the actual values in the table definition, whether these are DATE, DATETIME, or product of one of the supported functions, to determine which of the ahead-of-time partitions are already covered by existing schema, and which needs to be added.
  The function generates either ADD PARTITION or REORGANIZE PARTITION statements, based on whether MAXVALUE partition is present.
  There's a variety of conditions to make the function return an error: if the table is not temporal range partitioned, if the interval is invalid for the table, and more.
• TemporalRangePartitioningRetention(): given a table and an expiration time, this function returns a (possibly empty) ALTER TABLE DROP PARTITION ... statement dropping all expired partitions. Again, schemadiff computed the actual partition values whether explicit DATE, DATETIME or product of one of the supported functions.

Related Issue(s)

• Tracking: RFC: temporal partition rotation automation #17427
• Related: Tracking: Online DDL partitioning changes improved support #15674

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
• If this change is to be back-ported to previous releases, a justification is included in the PR description
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on CI?
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

Review Checklist

Hello reviewers! 👋 Please follow this checklist when reviewing this Pull Request.

General

• Ensure that the Pull Request has a descriptive title.
• Ensure there is a link to an issue (except for internal cleanup and flaky test fixes), new features should have an RFC that documents use cases and test cases.

Tests

• Bug fixes should have at least one unit or end-to-end test, enhancement and new features should have a sufficient number of tests.

Documentation

• Apply the release notes (needs details) label if users need to know about this change.
• New features should be documented.
• There should be some code comments as to why things are implemented the way they are.
• There should be a comment at the top of each new or modified test to explain what the test does.

New flags

• Is this flag really necessary?
• Flag names must be clear and intuitive, use dashes (-), and have a clear help text.

If a workflow is added or modified:

• Each item in Jobs should be named in order to mark it as required.
• If the workflow needs to be marked as required, the maintainer team must be notified.

Backward compatibility

• Protobuf changes should be wire-compatible.
• Changes to _vt tables and RPCs need to be backward compatible.
• RPC changes should be compatible with vitess-operator
• If a flag is removed, then it should also be removed from vitess-operator and arewefastyet, if used there.
• vtctl command output order should be stable and awk-able.

[dbussink]

I think we should make sure to also include sub-second precision here. I would expect a general conversion function to honor that.

[shlomi-noach]

Already reverted :)

[shlomi-noach]

Decided to never reverse-engineer a function value; always compute forward.

[codecov]

Codecov Report

Attention: Patch coverage is 79.29688% with 106 lines in your changes missing coverage. Please review.

Project coverage is 67.69%. Comparing base (56b5c2a) to head (d4fb9f9).
Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
go/vt/schemadiff/partitioning_analysis.go	77.35%	106 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17426      +/-   ##
==========================================
+ Coverage   67.60%   67.69%   +0.09%     
==========================================
  Files        1581     1583       +2     
  Lines      253945   254775     +830     
==========================================
+ Hits       171670   172462     +792     
- Misses      82275    82313      +38     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.