Algorithm to convert CCYYMM to number 1 - 18

[RICHINMINN]

I'm working with a DB2 database which is designed to hold 18 months'-worth of data, in 18 separate partitions. Does anyone have an algorithm that I can use to calculate the current month's partition on the database? I can do it for numbers of partitions that are multiples of 12, but having 18 partitions complicates things.

Thanks!

Rich (in Minn.)

 

[k5tm]

Rich,

Do you have integer-of-date, etc available to help with date arithmetic?

Tom Morrison

http://www.liant.com

 

[PHV]

Something like (12 * CCYY + MM) modulus 18 ?

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[k5tm]

And modulus arithmetic in COBOL is done with

DIVIDE month-count BY 18 giving who-cares REMAINDER partition-number.

Don't forget to add 1 if your partition number is not zero-relative...

Tom Morrison

http://www.liant.com

 

[k5tm]

So, Rich, did you have good results?

Tom Morrison

http://www.liant.com

 

[RICHINMINN]

k5tm,
What I ended up using was:
DIVIDE ((CCYY * 12) + MM) BY 18
GIVING PARTN-QUOTIENT
REMAINDER PARTN-REMAINDER.
IF PARTN-REMAINDER = 0
MOVE 18 TO PARTN-REMAINDER.

This gives me a range of 1 to 18. If I simply added 1 to PARTN-REMAINDER in all cases, I would also have 1 to 18, but a given year (January - December) would have partitions 2 through 13, not 1 through 12.

Thanks for everyone's input.

Rich (in Minn.)

 

[webrabbit]

Actually

DIVIDE ((CCYY * 12) + MM) BY 18
GIVING PARTN-QUOTIENT
REMAINDER PARTN-REMAINDER

would never give a result of 18 in PARTN-REMAINDER, so adding 1 in all cases is perfectly safe.

However, the above code is not valid COBOL sytax, and would not even compile with most compilers.