Strange behavior of GNUCash on large database

[perillamint]

Hello,

I'm trying to write NodeJS lib which manipulates GNUCash's postgres DB.

In small number of transactions (10k), it works fine. However, When I
pour lots of transactions(about 50k) in DB, it starts strange behavior.

It mixes income and expenses column and displays sum incorrectly.
(negative value)

I guess this caused by limitation of GNUcash's ability to handle large
data. Is there any documented limitation of GNUcash? or does anyone have
experience like this?

Thanks.

p.s. Sorry for bad English. I'm not English native.