This significantly speeds up the query which bookkeeper often does:
"SELECT created_index"
" FROM channelmoves"
" WHERE payment_hash = X'%s'"
" AND credit_msat = %"PRIu64
" AND created_index <= %"PRIu64,
On large databases this scan is expensive, and a payment_hash index
cuts it down a great deal. It does take longer to load the channelmoves
in the first place though (about 3x).
Before:
$ while sleep 10; do wc -l /tmp/bkpr-progress; done
169505 /tmp/bkpr-progress
196010 /tmp/bkpr-progress
219370 /tmp/bkpr-progress
235671 /tmp/bkpr-progress
244242 /tmp/bkpr-progress
255362 /tmp/bkpr-progress
265636 /tmp/bkpr-progress
276966 /tmp/bkpr-progress
284451 /tmp/bkpr-progress
288836 /tmp/bkpr-progress
296578 /tmp/bkpr-progress
304571 /tmp/bkpr-progress
After:
$ while sleep 10; do wc -l /tmp/bkpr-progress; done
161421 /tmp/bkpr-progress
238273 /tmp/bkpr-progress
281185 /tmp/bkpr-progress
305787 /tmp/bkpr-progress
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Changed: plugins: the sql plugin now keeps an index on `channelmoves` by `payment_hash`.
Any file in this directory which is executable and whose name only
consists of alphanumeric characters, space, '.', '-' or '_' will be
automatically loaded when lightningd starts (unless suppressed with
commandline options).
0c9a35e2d5