If restore from backup option is no aviable,
the information on BISTAX is on the BKARHINV table.
So the data on bistax can be populate, update or inserted from the bkarhinv table.
select * from BKISTAX where bkis_tax_invno = 123456789
select * from "BKARHINV" where bkar_inv_num = 123456789
Kelloggs
PD: the table duplicate itself??? how big is the table?? because if it reaches the limit pervasive will create BKISTAX.000, BKISTAX.001