Hi Vikrant,
Are you trying a full load and you are finding missing records? or you are doing delta/init load while you discover missing records?
It might be possible that some records are stored in previous periods that are not getting extracted. Also there is specific limits on 0FI_GL_4 type datasources where they only extract data in INIT or Delta mode till the timestamp of successful delta in table BWOM2_TIMEST.
Ideally, BKPF is header table and BSEG is segment so all the records which are there in BSEG must be present in BKPF and vice versa.
Thanks
Amit