Add opt-in event type index and adaptive EventLoader for sparse projections#4233
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…ctions When projections filter on a small subset of event types with large sequence gaps between matching events, the daemon's query can time out scanning through non-matching events. Two improvements: 1. Opt-in composite index on (type, seq_id): opts.Events.EnableEventTypeIndex = true Allows PostgreSQL to jump directly to matching event types. 2. Adaptive EventLoader with timeout-triggered fallback strategies: - Normal: standard range query with type filter - Skip-ahead: find MIN(seq_id) matching type filter, fetch from there - Window-step: advance in 10K windows until events found The loader automatically escalates through strategies on timeout, then resets to Normal when events are found. Closes #3705 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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) The skip-ahead / window-step fallback added in #4233 never engaged: 1. AutoClosingLifetime re-throws command failures through MartenExceptionTransformer, which wraps the timeout NpgsqlException/ PostgresException (SqlState 57014) into a MartenCommandException — not an NpgsqlException. isTimeoutException only inspected the outermost exception, so every real timeout was classified as non-timeout and the fallback was skipped. It now walks the inner-exception chain. 2. The escalation gate also required !EnableEventTypeIndex, but the (type, seq_id) composite index cannot serve a multi-type, globally seq_id-ordered LIMIT query, so the normal query still times out with the index on. The gate is now just _hasTypeFilter; the flag only controls the advisory warning text. Also guard the catch filter with !token.IsCancellationRequested so a deliberate daemon shutdown (OperationCanceledException) propagates cleanly instead of triggering pointless strategy escalation. Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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) Backport of the master fix to the 8.0 maintenance branch. The skip-ahead / window-step fallback added in #4233 never engaged: 1. AutoClosingLifetime re-throws command failures through MartenExceptionTransformer, which wraps the timeout NpgsqlException/ PostgresException (SqlState 57014) into a MartenCommandException — not an NpgsqlException. isTimeoutException only inspected the outermost exception, so every real timeout was classified as non-timeout and the fallback was skipped. It now walks the inner-exception chain. 2. The escalation gate also required !EnableEventTypeIndex, but the (type, seq_id) composite index cannot serve a multi-type, globally seq_id-ordered LIMIT query, so the normal query still times out with the index on. The gate is now just _hasTypeFilter; the flag only controls the advisory warning text. Also guard the catch filter with !token.IsCancellationRequested so a deliberate daemon shutdown (OperationCanceledException) propagates cleanly instead of triggering pointless strategy escalation. Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Summary
When projections filter on a small subset of event types and there are large sequence gaps between matching events, the daemon's event loading query can time out scanning through non-matching events.
Two improvements:
1. Opt-in composite index on (type, seq_id)
Creates
CREATE INDEX idx_mt_events_event_type_seq_id ON mt_events (type, seq_id)— allows PostgreSQL to jump directly to matching event types within a sequence range.2. Adaptive EventLoader with timeout-triggered fallback strategies
When a timeout occurs and the event type index is NOT enabled, the loader automatically escalates:
EnableEventTypeIndexCloses #3705
Test plan
🤖 Generated with Claude Code