ddl: support storage class table attributes

[Connor1996]

What problem does this PR solve?

Issue Number: ref #69625

Problem Summary:
TiDB currently lacks upstream SQL and metadata support for table and partition storage class attributes, so storage class intent cannot be expressed in DDL or surfaced through schema introspection.

What changed and how does it work?

• add STORAGE_CLASS syntax and ENGINE_ATTRIBUTE storage-class metadata
• support create, alter, add partition, and reorganize partition handling
• render storage-class metadata through SHOW CREATE TABLE
• expose storage-class metadata through INFORMATION_SCHEMA.TABLES and INFORMATION_SCHEMA.PARTITIONS
• add storage-class focused unit and integration coverage

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

• Parser coverage and focused DDL coverage pass locally.
• Storage-class integration coverage passes locally with 94 cases.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Add `STORAGE_CLASS` table and partition attributes, including `SHOW CREATE TABLE` and `INFORMATION_SCHEMA` exposure for storage class metadata.

[ti-chi-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR adds STORAGE_CLASS and ENGINE_ATTRIBUTE support across parser, metadata, DDL execution, information_schema exposure, and SHOW CREATE TABLE output, with unit and integration coverage.

Changes

Storage Class Feature

Layer / File(s)	Summary
Parser and AST support for STORAGE_CLASS pkg/parser/..., pkg/meta/model/.../BUILD.bazel	Adds STORAGE_CLASS keyword/token support, table-option grammar, restore support, and Bazel wiring for the parser and model packages.
Storage class parsing and application logic pkg/ddl/storage_class.go, pkg/ddl/partition.go, pkg/ddl/storage_class_*_test.go	Implements storage class JSON parsing, conflict checks, tier validation, table/partition assignment, and partition value matching helpers.
Engine attribute DDL job handling pkg/ddl/engine_attribute.go, pkg/ddl/job_worker.go, pkg/ddl/multi_schema_change.go	Adds CREATE TABLE engine attribute handling, ALTER TABLE job submission and execution, job worker dispatch, and multi-schema-change support for the new DDL action.
CREATE and ALTER TABLE wiring pkg/ddl/create_table.go, pkg/ddl/executor.go, pkg/ddl/partition.go, pkg/ddl/schematracker/dm_tracker.go, pkg/ddl/schematracker/BUILD.bazel, pkg/ddl/schematracker/dm_tracker_test.go	Wires storage class handling into CREATE TABLE, ALTER TABLE, add/reorganize partition flows, and schema-tracker persistence.
Information schema and SHOW CREATE TABLE pkg/infoschema/tables.go, pkg/executor/infoschema_reader.go, pkg/executor/show.go	Adds TIDB_STORAGE_CLASS columns, populates them in information schema output, and emits STORAGE_CLASS or ENGINE_ATTRIBUTE in SHOW CREATE TABLE.
Tests pkg/ddl/storage_class_test.go, pkg/ddl/storage_class_partition_test.go, tests/integrationtest/t/ddl/storage_class.test, tests/integrationtest/r/ddl/storage_class.result	Adds DDL unit tests, schema-tracker tests, and integration coverage for storage class parsing, partition behavior, and information schema output.

Estimated code review effort: 5 (Critical) | ~120 minutes

Suggested labels: sig/planner

Suggested reviewers: wjhuang2016, gengliqi, YangKeao

Poem

A rabbit hops through tiers of storage,
IA and STANDARD, snug in order.
Partitions dance, and CREATE TABLE sings,
STORAGE_CLASS glitters on tiny springs.
Hop, hop — the metadata’s in bloom 🐇

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title is concise and accurately summarizes the main change: adding storage class table attribute support.
Description check	✅ Passed	The description includes the required sections, issue reference, change summary, checklist, and release note, so it is mostly complete.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[codecov]

Codecov Report

❌ Patch coverage is 66.19718% with 240 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.9642%. Comparing base (b212b93) to head (1b288ce).

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #69605        +/-   ##
================================================
- Coverage   76.3234%   75.9642%   -0.3593%     
================================================
  Files          2041       2080        +39     
  Lines        560728     579424     +18696     
================================================
+ Hits         427967     440155     +12188     
- Misses       131860     137210      +5350     
- Partials        901       2059      +1158     

Flag	Coverage Δ
integration	45.8352% <66.1971%> (+6.1300%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	60.4471% <ø> (ø)
parser	∅ <ø> (∅)
br	64.0249% <ø> (+1.3036%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (3)

tests/integrationtest/t/ddl/storage_class.test (1)

36-44: 🎯 Functional Correctness | 🔵 Trivial | ⚡ Quick win

Missing integration coverage for the ENGINE_ATTRIBUTE fallback in SHOW CREATE TABLE.

This section only exercises SHOW CREATE TABLE for a simple no-scope, no-transition tier (STORAGE_CLASS='IA'). Per unit tests in pkg/ddl/storage_class_test.go (e.g. "with transitions falls back to engine attribute", "with scope falls back to engine attribute"), GetSimpleTableStorageClassForShowCreate declines and SHOW CREATE TABLE should render the raw ENGINE_ATTRIBUTE JSON instead of STORAGE_CLASS=... when transitions or scopes are present. There's no end-to-end integration test verifying that fallback rendering path.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@tests/integrationtest/t/ddl/storage_class.test` around lines 36 - 44, The
current storage class integration test only covers the simple STORAGE_CLASS='IA'
path, so add an end-to-end case that exercises the SHOW CREATE TABLE fallback
when GetSimpleTableStorageClassForShowCreate declines. Extend
TestStorageClassSyntaxSugarForTable with a table definition that includes
transitions or scope so SHOW CREATE TABLE renders raw ENGINE_ATTRIBUTE JSON
instead of STORAGE_CLASS=..., and verify the output before and after an ALTER
TABLE path if needed.

pkg/ddl/multi_schema_change.go (1)

315-317: 📐 Maintainability & Code Quality | 🔵 Trivial

Minor: could merge into the adjacent no-op case group for consistency.

ActionModifyEngineAttribute is functionally a no-op here just like the case above it; consider merging into the same case list (case model.ActionRebaseAutoID, model.ActionModifyTableComment, model.ActionModifyTableCharsetAndCollate, model.ActionModifyEngineAttribute:) for consistency with the existing style.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@pkg/ddl/multi_schema_change.go` around lines 315 - 317, The switch in
multiSchemaChange handling has a redundant no-op branch:
ActionModifyEngineAttribute behaves the same as the adjacent no-op cases. Merge
it into the existing case group in the relevant switch statement alongside
ActionRebaseAutoID, ActionModifyTableComment, and
ActionModifyTableCharsetAndCollate so the no-op actions are handled
consistently.

pkg/ddl/schematracker/dm_tracker_test.go (1)

132-164: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

LGTM! Solid coverage of the storage-class-rebuild-on-add-partition path for both range and list partitioning.

Consider optionally adding a negative case (new partition value falling outside the less_than/values_in scope) to confirm StorageClassTier is correctly left unset in that scenario.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@pkg/ddl/schematracker/dm_tracker_test.go` around lines 132 - 164, Add a
negative test alongside TestSchemaTrackerAddPartitionRebuildsStorageClass to
cover AddPartition when the new partition expression falls outside the existing
storage_class scope; use schematracker.NewSchemaTracker, execCreate, execAlter,
and mustTableByName to verify the resulting Partition.Definitions entry leaves
StorageClassTier unset instead of matching model.StorageClassTierIA.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@pkg/ddl/storage_class.go`:
- Around line 36-90: BuildStorageClassSettingsFromJSON treats nil as a default
STANDARD StorageClassSettings, not as “no settings”, so callers must not rely on
it to preserve an untouched storage_class. Update
onAlterTableStorageClassSettings to check for an absent/nil storage_class field
before calling BuildStorageClassSettingsFromJSON, mirroring the guard already
used by getStorageClassSettingsFromTableInfo. Keep the change localized to the
storage class handling path so the nil-input default behavior in
BuildStorageClassSettingsFromJSON remains intact.

---

Nitpick comments:
In `@pkg/ddl/multi_schema_change.go`:
- Around line 315-317: The switch in multiSchemaChange handling has a redundant
no-op branch: ActionModifyEngineAttribute behaves the same as the adjacent no-op
cases. Merge it into the existing case group in the relevant switch statement
alongside ActionRebaseAutoID, ActionModifyTableComment, and
ActionModifyTableCharsetAndCollate so the no-op actions are handled
consistently.

In `@pkg/ddl/schematracker/dm_tracker_test.go`:
- Around line 132-164: Add a negative test alongside
TestSchemaTrackerAddPartitionRebuildsStorageClass to cover AddPartition when the
new partition expression falls outside the existing storage_class scope; use
schematracker.NewSchemaTracker, execCreate, execAlter, and mustTableByName to
verify the resulting Partition.Definitions entry leaves StorageClassTier unset
instead of matching model.StorageClassTierIA.

In `@tests/integrationtest/t/ddl/storage_class.test`:
- Around line 36-44: The current storage class integration test only covers the
simple STORAGE_CLASS='IA' path, so add an end-to-end case that exercises the
SHOW CREATE TABLE fallback when GetSimpleTableStorageClassForShowCreate
declines. Extend TestStorageClassSyntaxSugarForTable with a table definition
that includes transitions or scope so SHOW CREATE TABLE renders raw
ENGINE_ATTRIBUTE JSON instead of STORAGE_CLASS=..., and verify the output before
and after an ALTER TABLE path if needed.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 3299c988-b78a-4d35-b390-d9dfe5d2846f

📥 Commits

Reviewing files that changed from the base of the PR and between b212b93 and ffd893d.

📒 Files selected for processing (27)

• pkg/ddl/BUILD.bazel
• pkg/ddl/create_table.go
• pkg/ddl/engine_attribute.go
• pkg/ddl/executor.go
• pkg/ddl/job_worker.go
• pkg/ddl/multi_schema_change.go
• pkg/ddl/partition.go
• pkg/ddl/schematracker/dm_tracker.go
• pkg/ddl/schematracker/dm_tracker_test.go
• pkg/ddl/storage_class.go
• pkg/ddl/storage_class_partition_test.go
• pkg/ddl/storage_class_test.go
• pkg/executor/infoschema_reader.go
• pkg/executor/show.go
• pkg/infoschema/tables.go
• pkg/meta/model/BUILD.bazel
• pkg/meta/model/engine_attribute.go
• pkg/meta/model/job_args.go
• pkg/meta/model/table.go
• pkg/parser/ast/ddl.go
• pkg/parser/keywords.go
• pkg/parser/keywords_test.go
• pkg/parser/misc.go
• pkg/parser/parser.go
• pkg/parser/parser.y
• tests/integrationtest/r/ddl/storage_class.result
• tests/integrationtest/t/ddl/storage_class.test

[Connor1996]

Addressed the remaining user-visible review gap in 5c44734 by adding integration coverage for the SHOW CREATE TABLE fallback path when storage class settings include transitions. The new case verifies raw ENGINE_ATTRIBUTE rendering on create and alter, then confirms SHOW CREATE switches back to STORAGE_CLASS syntax after altering back to a simple tier.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign benjamin2037, terry1purcell for approval. For more information see the Code Review Process.
Please ensure that each of them provides their approval before proceeding.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS
• pkg/ddl/OWNERS
• pkg/infoschema/OWNERS
• pkg/meta/OWNERS
• pkg/parser/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[Connor1996]

Addressed the remaining low-risk review follow-ups in 1b288ce826:

• merged ActionModifyEngineAttribute into the adjacent multi-schema no-op case list
• extended TestSchemaTrackerAddPartitionRebuildsStorageClass with out-of-scope range/list cases

While adding the negative coverage, I verified the current storage-class contract is to fall back to STANDARD when a partition does not match the configured scope, so I kept that behavior and codified it in the test instead of changing semantics here.