cockroach is having problems with huge transactions and
having them complete before timeouts or whatever, so
do smaller transactions.
because we can have partial recording of payments which
are not unique, we have to do a thing where we read and
check if it already exists before writing. this is not
concurrency safe.
Change-Id: Ia7d59499a43ce6d70cb2a23754edbdd1b643ef1a
using redash i manually checked that the only times the sum of
the payments does not match the paid column is for 2020-12 and
if it does not match then there are no payments.
Change-Id: I71ce0571de7e38e21548d7d6757b25abc3bfa781
