Re: Another Question about variable length fields

[CRPence <CRPbottle@xxxxxxxxx>]

Vern Hamberg wrote:
> I'll check the data - I thought I had some that was longer than
> the allocation, but the fields were defined as only 10 bytes -
> maybe it keeps things that short in the main space - that'd be an
> interesting optimization.

  There is a minimum amount of varlen storage required to effect 
creation of an auxiliary SID for a column.  I do not recall the 
minimal length, but perhaps nearly eighteen bytes to account both 
the data length and the effective address within the aux piece. 
With an explicit versus defaulted ALLOCATE(0), that may force to the 
aux regardless.  The /porting/ documents suggest character fields 
under forty bytes should be CHAR instead of VARCHAR with no 
allocation, to get more similar performance results to other SQL 
databases.  Creating additional fields and\or creating a longer 
varlen\varchar field will likely be required to get the auxiliary 
segment created for the file after at least one row requires the 
overflow to the aux storage area.

 IIRC someone made a change to ensure that after two RGZPFM with no 
data in the aux SID then it is either truncated or destroyed; after 
one reorganize, the auxiliary storage area may persist to maintain 
performance accommodations for update & insert activity.

Regards, Chuck