# What this PR does
After deploying
[`r439-v1.12.0`](https://github.com/grafana/oncall-private/releases/tag/r439-v1.12.0)
to staging, I noticed that the migrations were taking a long time, and
caused some wonkiness (see
https://raintank-corp.slack.com/archives/C08063QES5N).
```bash
Apply all migrations: [redacted secret grafana-admin-creds:admin-user], alerts, auth, auth_token, base, contenttypes, email, exotel, fcm_django, google, heartbeat, labels, mobile_app, oss_installation, phone_notifications, schedules, sessions, slack, social_django, telegram, twilioapp, user_management, webhooks, zvonok
Running migrations:
source=engine:app google_trace_id=none logger=apps.alerts.migrations.0063_migrate_channelfilter_slack_channel_id Starting migration to populate slack_channel field.
source=engine:app google_trace_id=none logger=apps.alerts.migrations.0063_migrate_channelfilter_slack_channel_id Bulk updated 1 ChannelFilters with their Slack channel.
source=engine:app google_trace_id=none logger=apps.alerts.migrations.0063_migrate_channelfilter_slack_channel_id Finished migration to populate slack_channel field.
Applying alerts.0063_migrate_channelfilter_slack_channel_id... OK
source=engine:app google_trace_id=none logger=apps.alerts.migrations.0064_migrate_resolutionnoteslackmessage_slack_channel_id Starting migration to populate slack_channel field.
source=engine:app google_trace_id=none logger=apps.alerts.migrations.0064_migrate_resolutionnoteslackmessage_slack_channel_id Bulk updated 1 ResolutionNoteSlackMessage records with their Slack channel.
source=engine:app google_trace_id=none logger=apps.alerts.migrations.0064_migrate_resolutionnoteslackmessage_slack_channel_id Finished migration to populate slack_channel field.
Applying alerts.0064_migrate_resolutionnoteslackmessage_slack_channel_id... OK
source=engine:app google_trace_id=none logger=apps.schedules.migrations.0019_auto_20241021_1735 Starting migration to populate slack_channel field.
source=engine:app google_trace_id=none logger=apps.schedules.migrations.0019_auto_20241021_1735 Bulk updated 6 OnCallSchedules with their Slack channel.
source=engine:app google_trace_id=none logger=apps.schedules.migrations.0019_auto_20241021_1735 Finished migration to populate slack_channel field.
Applying schedules.0019_auto_20241021_1735... OK
source=engine:app google_trace_id=none logger=apps.user_management.migrations.0026_auto_20241017_1919 Starting migration to populate default_slack_channel field.
source=engine:app google_trace_id=none logger=apps.user_management.migrations.0026_auto_20241017_1919 Bulk updated 1 organizations with their default Slack channel.
source=engine:app google_trace_id=none logger=apps.user_management.migrations.0026_auto_20241017_1919 Finished migration to populate default_slack_channel field.
Applying user_management.0026_auto_20241017_1919... OK
```
**NOTE**: wrt these migrations already being run for certain OSS stacks;
it shouldn't have much of an impact on OSS deployments, as it's really
only an issue for _very large_ versions of these tables (particularly
the `ResolutionNoteSlackMessage` table, which by its nature, has a
tendency to generate a lot of data).
## Checklist
- [ ] Unit, integration, and e2e (if applicable) tests updated
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required)
- [ ] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
show up in the autogenerated release notes.