You may find additional answers in my last email.
However, I'll try to adress some of your questions.
> a. Are there any new connections happening, how this table is getting populated?
Check my last email.
> b. How did you concluded that above sql statement leads to error,
> because this error doesn't seem to occur in path of above sql
> statement.
The errors appear when I added the second threads.
> c. Are there any other sql statements in connection where you see this error?
This is the only statement that generat this error.
> Can you explain a bit more about your scenario, so that this error
> can be reproduced easily.
Please check my last full detailed email.
> Some comments about SQL statements:
> a. table name provided as part of schema (mystat) is different
> from one used in sql statement(my_stat)
Sorry, for the typos
> b. definition of sequence mystat_sequence is missing, although it
> doesn't seem to be necessary, but if you can provide the definition
> you are using
> then it will be better.
The definition of the sequence is provided in my detailed email among
other things too.