Update migration transaction docs to reflect EF Core 9 single-transaction behavior - #5439
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AndriySvyryd with Copilot wants to merge 5 commits into
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Update migration transaction docs to reflect EF Core 9 single-transaction behavior#5439AndriySvyryd with Copilot wants to merge 5 commits into
AndriySvyryd with Copilot wants to merge 5 commits into
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[WIP] Clarify EF Core 9 migration transaction behavior
Update migration transaction docs to reflect EF Core 9 single-transaction behavior
Jul 30, 2026
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| In addition, starting with EF Core 9, all pending migrations are applied within a single transaction. Prior to EF Core 9, each migration was wrapped in its own transaction. If any migration fails, the entire transaction is rolled back, leaving the database in the state it was in before `Migrate()` or `MigrateAsync()` was called. | ||
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Done in 8e8df09.
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| In most cases, EF Core will automatically wrap each migration in its own transaction when applying migrations. Unfortunately, some migrations operations cannot be performed within a transaction in some databases; for these cases, you may opt out of the transaction by passing `suppressTransaction: true` to `migrationBuilder.Sql`. | ||
| In most cases, EF Core will automatically wrap migrations in a transaction when applying migrations. Prior to EF Core 9, each migration was wrapped in its own transaction. Starting with EF Core 9, all pending migrations are applied within a single transaction as part of [migration locking](xref:core/managing-schemas/migrations/applying#migration-locking). Unfortunately, some migration operations cannot be performed within a transaction in some databases; for these cases, you may opt out of the transaction by passing `suppressTransaction: true` to `migrationBuilder.Sql`. |
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@copilot Make the changes here more concise as this behavior is only present in EF Core 9, in 10 it was reverted.
Make a low-impact breaking changes note for 9 for this
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Done in the latest commit. managing.md now restores the original per-migration transaction text with a concise NOTE pointing to a new Low-impact breaking changes entry added to ef-core-9.0/breaking-changes.md that describes the EF Core 9-specific single-transaction behavior (and notes it was reverted in EF Core 10).
…e for EF Core 9 single-transaction migrations
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Pull request overview
This PR updates EF Core documentation to clarify the migration transaction behavior change introduced in EF Core 9 (spanning all pending migrations in a single transaction), and links that behavior to relevant migration-locking/breaking-change documentation.
Changes:
- Adds a new EF Core 9 breaking-change entry documenting the single-transaction behavior when applying multiple pending migrations.
- Updates the “Managing migrations” docs to call out the EF Core 9 behavior and link to the breaking-change note.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| entity-framework/core/what-is-new/ef-core-9.0/breaking-changes.md | Adds a breaking-change row and a new section describing the EF Core 9 migration transaction scope change and mitigation guidance. |
| entity-framework/core/managing-schemas/migrations/managing.md | Adds an EF Core 9 note to qualify the general “per-migration transaction” guidance and links to the breaking-change note. |
Comments suppressed due to low confidence (3)
entity-framework/core/what-is-new/ef-core-9.0/breaking-changes.md:466
- This sentence points readers to the migration locking section but also implies the single-transaction behavior is "as part of" migration locking. The linked section currently explains the lock but not the transaction scope, so readers may not find the details here. Rewording to separate the behaviors would make this clearer.
Starting with EF Core 9.0, all pending migrations are applied within a single transaction as part of [migration locking](xref:core/managing-schemas/migrations/applying#migration-locking). If any migration fails, the entire transaction is rolled back. This behavior was reverted in EF Core 10.
entity-framework/core/what-is-new/ef-core-9.0/breaking-changes.md:474
- The mitigation "upgrade to EF Core 10" isn't actionable for users who are evaluating or constrained to EF Core 9. It would be more helpful to describe an EF Core 9 workaround (e.g., applying migrations via generated SQL scripts) and optionally mention that EF Core 10+ reverted this behavior.
#### Mitigations
If you need per-migration transaction behavior in EF Core 9, upgrade to EF Core 10, which reverts to wrapping each migration in its own transaction.
entity-framework/core/what-is-new/ef-core-9.0/breaking-changes.md:466
- The PR description says
applying.mdwas updated to document the single-transaction behavior in the Migration locking section, but the current Migration locking section doesn't mention transaction scope/rollback. Either updateapplying.mdas described, or adjust the PR description to match what's actually changed.
Starting with EF Core 9.0, all pending migrations are applied within a single transaction as part of [migration locking](xref:core/managing-schemas/migrations/applying#migration-locking). If any migration fails, the entire transaction is rolled back. This behavior was reverted in EF Core 10.
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
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Pull request overview
Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.
Comments suppressed due to low confidence (3)
entity-framework/core/managing-schemas/migrations/managing.md:202
- The main sentence still reads as if per-migration transactions apply generally, but EF Core 9’s default is a single transaction across all pending migrations. Since this paragraph is often quoted/snippet-linked, it should be version-qualified in the main text (not only in the NOTE) to avoid misleading EF Core 9 readers.
In most cases, EF Core will automatically wrap each migration in its own transaction when applying migrations. Unfortunately, some migration operations cannot be performed within a transaction in some databases; for these cases, you may opt out of the transaction by passing `suppressTransaction: true` to `migrationBuilder.Sql`.
> [!NOTE]
> In EF Core 9, EF Core spans all pending migrations with a single transaction by default (this was reverted in EF Core 10). See [the breaking change note](xref:core/what-is-new/ef-core-9.0/breaking-changes#migrations-single-transaction) for details.
entity-framework/core/what-is-new/ef-core-9.0/breaking-changes.md:466
- The sentence links the single-transaction behavior to the migration locking docs section, but that section doesn’t currently document the transaction-scope change. This makes the link misleading; either add the missing detail there, or reword here to describe the behavior without implying that the linked section explains it.
Starting with EF Core 9.0, all pending migrations are applied within a single transaction as part of [migration locking](xref:core/managing-schemas/migrations/applying#migration-locking). If any migration fails, the entire transaction is rolled back. This behavior was reverted in EF Core 10.
entity-framework/core/what-is-new/ef-core-9.0/breaking-changes.md:474
- The mitigation currently suggests upgrading to EF Core 10 as the only option. That’s a significant jump (and may require a newer .NET runtime), so it would be helpful to also document an EF Core 9-specific mitigation (e.g., applying migrations one at a time by targeting a specific migration).
#### Mitigations
If you need per-migration transaction behavior in EF Core 9, upgrade to EF Core 10, which reverts to wrapping each migration in its own transaction.
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The migration docs described a per-migration transaction model that no longer applies in EF Core 9+, where all pending migrations run inside a single transaction. This mismatch confused users upgrading from EF Core 8.
Changes
managing.md: Updated the transaction behavior description to distinguish pre-EF Core 9 (per-migration transaction) from EF Core 9+ (single transaction across all pending migrations), with a link to the migration locking section.applying.md: Added a paragraph in the Migration locking section explicitly documenting that all pending migrations run in a single transaction starting with EF Core 9, including the rollback-on-failure behavior.