Numeric overflow error while calculation

Dear Experts,

     I have created a calculation view. the var_out statement looks like

  select a,b,.....

,

CASE WHEN "Field1"=1

THEN 1/7

ELSE "Field1"*"Field2"/"Field3"

END  AS "Field4",

from table a, table b

I get the following error

314]: numeric overflow:  [314] INF126293.PROC_TEST1: line 203 col 1 (at pos 4849): numeric overflow exception: numeric overflow: search table error:  [6944] AttributeEngine: overflow in numeric calculation;JECalculate pop12(setResultFromTo(0, 2147483647),addExpression('box ( "schema1.table b.fiels 1" , 1 , ( decfloat ( 1 ) / decfloat ( 7 ) ) , ( decfloat ( ( "schema1._SYS_CE_LLANG_5162F1DF92976332E10000000A9CF502_TMP:IT_0x7f77228e13500x7f76ee07c800:1@vid:2.VAL0000" * "INF126293._SYS_CE_LLANG_5162F1DF92976332E10000000A9CF502_TMP:IT_0x7f77228e13500x7f76ee07c800:1@vid:2.BILL_OFFPEAK" ) ) / decfloat ( "schema1"._SYS_CE_LLANG_5162F1DF92976332E10000000A9CF502_TMP:IT_0x7f77228e13500x7f76ee07c800:1@vid:2.USAGE_OFFPEAK_TOTAL" ) ) )'),addViewAttribute('_CV0x7f77228e2f40'))

what could be the reason behind the error

Thanks,

Rajesh.