An open question has been whether with varchar and char Redshift when moving rows to memory, either during data load (COPY) or query processing, allocates the f

An open question has been whether with varchar and char Redshift when moving rows to memory, either during data load (COPY) or query processing, allocates the full length of the string as specified in the DDL, or only the allocates the actual length of the string. Four query steps were investigated (aggr, hash, sort and unique) and for all of them varchar does not allocate its full length in the DDL, but rather only the length of the actual string, but char does allocate the full length in the DDL, regardless of the length of the actual string. It seems not entirely unreasonable, although certainly it is not proven, to imagine these findings may be generally true for query processing. No findings were made for behaviour during data load.