Archiving Streams

session.Events.ArchiveStream(streamId);
session.Events.UnArchiveStream(streamId);
await session.SaveChangesAsync();

Archiving sets is_archived on fi_streams. The events stay; the stream is simply marked as no longer live.

What archiving affects

• An archived stream refuses further appends, with ArchivedStreamException — which derives from JasperFx.Events.ArchivedStreamException, so a store-agnostic catch works on Marten and Polecat too. Archiving is not a soft delete you can keep writing through; unarchive it first if that is really the intent.
• A natural key no longer resolves an archived stream. The lookup joins fi_streams, so the flag is read off the join rather than being copied.
• An archived stream is excluded from the explorer's recent-streams read.
• The events remain in fi_events and remain visible to the async daemon and to stream reads.

WARNING

Starting a stream over an archived id is still a collision, not an archive refusal — you get ExistingStreamIdCollisionException. An archived id is an id in use, and a caller who reused one needs a different id rather than an unarchive.

Archiving through an Archived event

A single stream projection that owns the stream archives it when it sees JasperFx.Events.Archived, inline or through the daemon:

session.Events.Append(streamId, new Archived("Closed out"));
await session.SaveChangesAsync();

"Owns" is the operative word: only a projection with a snapshot for that stream — either one it loaded or one this slice produced — archives it, so sibling projections in a composite do not fire phantom archives.

TIP

The direct operation is Fisher's own route and needs no projection at all, which is why its natural key tables carry no is_archived column: Polecat copies the flag and keeps it in sync from a projection watching for the event, which then needs a second, rebuild-time entry point — because a daemon rebuild replays events without appending streams and would otherwise leave the table empty after teardown. Nothing here watches for anything, so there is nothing to repopulate.

Tombstoning

session.Events.TombstoneStream(streamId);

A tombstone marks a stream as abandoned. Use it when a stream was created in error and its events should not be interpreted.

Archiving is not deletion

The events are still there and still occupy space. If you want them gone, the options are:

Want	Use
The stream's history collapsed to one snapshot event	Stream compacting
Protected information removed from event bodies	Event data masking
Everything gone	DeleteAllEventDataAsync

WARNING

Deleting events is safe only because fi_events.seq_id is AUTOINCREMENT. A bare INTEGER PRIMARY KEY aliases the rowid, which SQLite reuses after a delete, and a reused sequence below the daemon's high-water mark is an event no async projection would ever see.

Archiving and projections

An archived stream's events are unchanged, so a projection that already folded them keeps what it derived. Archiving is a statement about the stream, not a correction to anything built from it — if you need a projection to forget it, rebuild the projection.

Statistics

Archived and compacted streams are why EventSequenceNumber can exceed EventCount:

var stats = await store.Advanced.FetchEventStoreStatisticsAsync();

See Event Storage.