Places:Migration

Places Migration Scenarios

Need to detail the up/down/sidegrade scenarios for Places, how they're handled.

Upgrades:

from	to	action	notes
<=2.*	3.0a2	history moves to Places
3.0a2	3.0a3	some schema changes	XXX bug#s
<=2.*	3.0a4	history and bookmarks move to Places
3.0a2	3.0a4	bookmarks move to Places

Testing

We need an automated way of testing migrations:

• First install, no profiles
  • Test migration from each supported browser/external-app
• Upgrades from major versions
• Downgrades to major versions
• Sidegrades between locales, partner builds, other

Also, we need to detail a policy regarding support for foward/backward/ad-infinitum support for bookmarks.

• • • DRAFT *** DRAFT *** DRAFT ***

Notes on handling schema changes for bookmarks:

• Bookmarks from places.sqlite will be backed up to bookmarks.html at shutdown.
• For the upgrade from Places-no-bookmarks to Places-bookmarks, we'll delete and re-initialize the bookmarks tables.
• For subsequent schema changes we'll write migration code.
• Since SQLite doesn't allow column drops, those changes will require staging the data in a temporary table, dropping the old table, and then renaming the new table.
• The dump approach can be lossy, so it's key that we evaluate the necessity of this and fix any data-loss moving forward.
• Bookmarks.html is archived to the {profile dir}/bookmarkbackups directory (like Fx2).
• If you downgrade from Fx3 to Fx2, you'd get any new bookmarks, as Fx2 will use the boomkarks.html file.
• If you then upgrade again to Fx3, new Fx2 bookmarks are not automatically re-imported, as that only happens on a schema change. The user can import manually.
• The export code needs to export and import microsummaries and livemarks, which
• As far as exporting other data to avoid a lossy transition from schema x to schema y, we might write out attributes in bookmarks.html, but we need to make sure Fx2 and other browser can handle that gracefully.
• We don't want to dump/import on every schema change. Only if necessary, as some (inevitable) schema changes can be done with migration code.

Bugs:

• bug 374876 - write out bookmarks.html on close
• bug 374640 - upgrade from 3a* -> 3a3 breaks stuff
• bug 373239 - add schema versioning