Re: SYSPARTITIONSTAT and "Average Row Size"

On 08-Sep-2015 14:06 -0600, rob wrote:

What is the point of "Average Row Size" (AVGROWSIZE) as a column if
you're just going to make it a -1 if there are any variable length
fields or LOB fields?

My SWAG is that the column is there mostly for /compatibility/ reasons, because the column is available in other DB2 flavors.

Just what else is going to happen to cause two
rows of unequal length that you may need to compute an "average" row
length?
[http://www.ibm.com/support/knowledgecenter/ssw_ibm_i_72/db2/rbafzcatsyspstat.htm]
<<SNIP>>

AFaIK that statistic is maintained on other DB2 databases, but is for row compression; a feature not available on DB2 for i. The value -1 in the DB2 LUW means, IIRC, that the "statistics are not collected"; that certainly agrees with the described effect for DB2 for i. Given the DB2 for i does not maintain a statistic [as an average] of how much data in a row is [un]used [due to compression], the only means to calculate that value would be to actually access the data [during the query request to present the statistic] in order to calculate the value; that would be very likely to take much longer than the UDF would be allowed to run before the time-out.