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Diffstat (limited to 'doc/development/background_migrations.md')
| -rw-r--r-- | doc/development/background_migrations.md | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/doc/development/background_migrations.md b/doc/development/background_migrations.md index e67db9ff142..f83a60e49e8 100644 --- a/doc/development/background_migrations.md +++ b/doc/development/background_migrations.md @@ -7,6 +7,11 @@ storing data in a single JSON column the data is stored in a separate table. ## When To Use Background Migrations +>**Note:** +When adding background migrations _you must_ make sure they are announced in the +monthly release post along with an estimate of how long it will take to complete +the migrations. + In the vast majority of cases you will want to use a regular Rails migration instead. Background migrations should _only_ be used when migrating _data_ in tables that have so many rows this process would take hours when performed in a @@ -91,6 +96,10 @@ BackgroundMigrationWorker.perform_bulk_in(5.minutes, jobs) ## Cleaning Up +>**Note:** +Cleaning up any remaining background migrations _must_ be done in either a major +or minor release, you _must not_ do this in a patch release. + Because background migrations can take a long time you can't immediately clean things up after scheduling them. For example, you can't drop a column that's used in the migration process as this would cause jobs to fail. This means that |