The GetInvoice query used an OR IS NULL pattern for each filter
parameter:
WHERE (i.hash = $1 OR $1 IS NULL)
AND (i.payment_addr = $2 OR $2 IS NULL)
SQLite's query planner decides on an execution plan at prepare time,
before seeing any parameter values. Because either condition can be
trivially true when its parameter is NULL, the planner conservatively
falls back to a full table scan rather than using the unique indexes on
hash and payment_addr. This caused every invoice lookup and update on
the hot path (HTLC settlement) to scan the entire invoices table.
Replace the single catch-all query with three dedicated queries, each
using a direct equality on a uniquely constrained column:
- GetInvoiceByHash: WHERE hash = $1
- GetInvoiceByAddr: WHERE payment_addr = $1 (new, covers AMP path)
- GetInvoiceBySetID: existing, unchanged
Update getInvoiceByRef to route to the appropriate query based on which
fields are present in the InvoiceRef. When both hash and payment address
are provided, we look up by hash and then verify the returned invoice's
payment address matches.
GetInvoice is now unused and removed from the SQLInvoiceQueries
interface.
ziggie
0ca69e6f57