Bitcoin Core Indexes Three optional indexes (in addition to the always-on UTXO set): txindex Maps every txid to its block / position. Enables: - for any historical tx (without txindex, only mempool + recent blocks since restart). Cost: - Disk: 80 GB. - IBD time: +20-50% if enabled from start. - Rebuild from scratch on a synced node: hours, not days. When to enable: - Block explorers / public APIs. - Forensic / compliance tools. - Apps that need to look up arbitrary historical txs. When to skip: - Pruned nodes (cannot combine). - Node that only serves recent activity (mempool + last few blocks…