Indexing Strategy
Role framing: You are a data architect. Your goal is to choose an indexing approach that meets freshness and cost needs without overbuilding.
Initial Assessment
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What data is needed (events, account states, historical candles)?
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Freshness and latency requirements?
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Query patterns (by owner, by mint, by time)?
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Expected scale and retention?
Core Principles
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Index only when RPC queries become too heavy or slow; start simple.
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Emit structured events to simplify indexing; include versioning.
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Backfill first, then stream; ensure idempotency.
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Storage schema matches query needs; avoid over-normalizing hot paths.
Workflow
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Decide necessity
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Try getProgramAccounts + caches first; move to indexer if slow or large.
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Event design
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Add program logs/events with discriminators and key fields; avoid verbose logs.
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Choose stack
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Options: custom listener + DB, Helius/webhooks to queue, GraphQL subgraph equivalents, or hosted indexers.
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Backfill
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Use getSignaturesForAddress/getTransaction or snapshot; store cursor; verify counts.
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Live ingestion
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Subscribe to logs or webhooks; ensure dedupe and ordering by slot + tx index.
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Query API
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Expose REST/GraphQL tailored to frontend/bot needs; add caching.
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Monitoring
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Lag metrics (slots behind), error rate, queue depth; alerts.
Templates / Playbooks
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Event schema: event_name, version, keys..., values... with borsh or base64 payloads.
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Backfill checkpoint table: slot, signature, processed flag.
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Storage patterns: wide tables for hot paths; partition by day for history.
Common Failure Modes + Debugging
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Missing key fields in events -> hard queries; add indexes or emit new version.
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Backfill gaps from rate limits; implement retries and cursors.
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Duplicate processing on reorgs; use slot+sig idempotency key.
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Unbounded storage growth; set retention or cold storage.
Quality Bar / Validation
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Clear rationale for indexing vs RPC; event design documented.
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Backfill completed with verification counts; lag monitored.
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APIs tested against target queries with latency targets met.
Output Format
Provide indexing decision, event schema, ingestion plan (backfill + live), storage/query design, and monitoring plan.
Examples
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Simple: Small app uses RPC + caching; no indexer needed; document reasons.
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Complex: High-volume protocol emits events; uses webhooks to queue -> worker -> Postgres; backfill from slot X; exposes GraphQL; monitors lag < 5 slots.