Storage Requirements

The local txs DB grows with the amount of data you index. Each chain has its own file (mevlog-txs-v1-{chain_id}.db), plus a -wal / -shm sidecar during writes. Check actual usage at any time with mevlog db-info --chain-id <id>.

Mainnet sizing estimates

Estimated from a contiguous week of Ethereum mainnet (~0.28 MB/block of raw data, ~307 txs and ~869 logs per block). Logs dominate - roughly 80% of the data. Your numbers will vary with traffic.

Plan for ~1.5-1.7 TB per year of disk if you index all of Mainnet and keep indexes. Most chains are far lighter, and you rarely need the full chain - index only the ranges you query.

Reducing storage usage

• index --live --keep N holds a rolling window of the newest N blocks.
• purge-db --keep N --chain-id <id> drops older data on demand; add --reclaim to VACUUM and actually shrink the file (otherwise freed pages are reused, not returned to the OS).

Indexes

mevlog ships with only a couple of minimal indexes (e.g. on tx_hash). Broad indexes are deliberately not created by default - they would inflate the storage size.

If you run heavy queries over a large store and notice slowdowns, add indexes that match your query patterns. The query connection is read-only, so create them by opening the file directly with the sqlite3 CLI:

sqlite3 ~/.mevlog/mevlog-txs-v1-1.db \
  "CREATE INDEX idx_logs_address ON logs (address, block_number);"

Index what your WHERE clauses filter on (a log address, a from_address, etc.). The trade-off is always the same: faster reads - larger file.