Event Storage

Polecat stores events in SQL Server 2025 using three core tables.

pc_events

The main event log table:

Column	Type	Description
seq_id	bigint IDENTITY(1,1)	Global sequence number (PK)
id	uniqueidentifier	Unique event ID
stream_id	uniqueidentifier or nvarchar(250)	Stream identifier
version	int	Position within the stream
data	json	Serialized event body
type	nvarchar(250)	Event type name (snake_case)
timestamp	datetimeoffset	When the event was recorded
tenant_id	nvarchar(250)	Tenant identifier
dotnet_type	nvarchar(500)	Full .NET type name
correlation_id	nvarchar(250)	Request correlation
causation_id	nvarchar(250)	Event causation chain
headers	json	Custom metadata headers
is_archived	bit	Archive flag

pc_streams

Stream metadata:

Column	Type	Description
id	uniqueidentifier or nvarchar(250)	Stream identifier (PK)
type	nvarchar(250)	Aggregate type name
version	int	Current stream version
timestamp	datetimeoffset	Last event timestamp
created	datetimeoffset	Stream creation time
snapshot	json	Latest snapshot data
snapshot_version	int	Snapshot version
tenant_id	nvarchar(250)	Tenant identifier
is_archived	bit	Archive flag

pc_event_progression

Async daemon progress tracking:

Column	Type	Description
name	nvarchar(250)	Projection/subscription name (PK)
last_seq_id	bigint	Last processed sequence ID
last_updated	datetimeoffset	Last update timestamp

Event Type Naming

Polecat converts .NET event type names to snake_case for storage:

• QuestStarted → quest_started
• MembersJoined → members_joined
• InvoiceLineItemAdded → invoice_line_item_added

Sequence IDs

Events are assigned a global, monotonically increasing sequence ID via SQL Server's IDENTITY(1,1). This provides a total ordering of all events across all streams, which is critical for the async daemon's event processing.

JSON Storage

Event data and headers are stored using SQL Server 2025's native json type, serialized with System.Text.Json.