make execution index more compact

[pk910]

Summary

Introduces tx_uid — a compact 8-byte transaction identifier that replaces the redundant (block_uid, tx_hash) composite key in execution indexing tables, significantly reducing storage and index overhead.

tx_uid encoding

tx_uid = block_uid << 16 | tx_index
       = (slot << 16 | block_unique_index) << 16 | tx_position

• block_uid recoverable as tx_uid >> 16
• tx_index recoverable as tx_uid & 0xFFFF
• slot recoverable as tx_uid >> 32
• Max slot ~2.1B (signed BIGINT) = 817+ years on mainnet at 12s slots

Schema changes

el_transactions — keeps block_uid, adds tx_uid, drops tx_index:

• tx_uid added as a UNIQUE indexed column (block_uid << 16 | tx_index)
• tx_index dropped (derivable from tx_uid & 0xFFFF)
• Primary key remains (block_uid, tx_hash) for efficient block-based and hash-based lookups

el_event_index — (block_uid, tx_hash, event_index) → (tx_uid, event_index):

• Drops block_uid (8 bytes) and tx_hash (32 bytes)
• Replaces with tx_uid (8 bytes)
• Saves 32 bytes per row

el_token_transfers — (block_uid, tx_hash, tx_idx) → (tx_uid, tx_idx):

• Drops block_uid (8 bytes), tx_hash (32 bytes), and tx_pos (4 bytes)
• Replaces with tx_uid (8 bytes)
• Saves 36 bytes per row

el_transactions_internal — (block_uid, tx_hash, tx_callidx) → (tx_uid, tx_callidx):

• Drops block_uid (8 bytes) and tx_hash (32 bytes)
• Replaces with tx_uid (8 bytes)
• Saves 32 bytes per row

Storage reduction estimate

Assumptions: mainnet-scale, 200 txs/block, ~2.5 events/tx, ~4 token transfers/tx, ~6.5 internal calls/tx.

Estimates include heap data + all associated indexes (PK + secondary). Dependent tables see large reductions because the 32-byte tx_hash and 8-byte block_uid are replaced by a single 8-byte tx_uid in both row data and every index entry.

Table	Row data	PK key size	Removed indexes	Reduction
el_event_index	-32 bytes/row	44 → 12 bytes	tx_hash_idx	~47%
el_token_transfers	-36 bytes/row	44 → 12 bytes	tx_hash_idx, block_uid_idx	~42%
el_transactions_internal	-32 bytes/row	44 → 12 bytes	tx_hash_idx	~47%
el_transactions	+4 bytes/row	unchanged	swapped block_uid_idx → tx_uid_idx	~0%

The three dependent tables hold ~93% of all execution index rows (events, transfers, and internal calls vastly outnumber transactions). The weighted overall reduction across all four tables is approximately ~45%.

Query changes

• Dependent table queries now use tx_uid instead of (block_uid, tx_hash) for all lookups
• ORDER BY block_uid DESC, tx_index DESC → ORDER BY tx_uid DESC (equivalent ordering)
• Address page handlers batch-fetch tx_hash from el_transactions via GetElTransactionsByTxUids() when needed for display
• Cleanup uses WHERE tx_uid < threshold for dependent tables (threshold = blockUidThreshold << 16)

Migration

The migration (20260417000000_tx-uid) performs the following in a single transaction:

1. Adds tx_uid column to el_transactions and populates it
2. Recreates each dependent table with tx_uid via JOIN, migrating existing data
3. Drops tx_index from el_transactions
4. Rebuilds all affected indexes

Both PostgreSQL and SQLite migrations are included.

Test plan

• Run migration on a database with existing execution index data
• Verify transaction detail page shows correct data (events, transfers, internal txs tabs)
• Verify address page shows correct token transfers and internal transactions
• Verify slot page still enriches transactions with EL data
• Verify new blocks are indexed correctly after migration
• Verify retention cleanup still works (deletes old data by block threshold)
• Verify reorg handling (orphaned blocks have distinct tx_uids)