0.5.1
Released: November 16, 2021
Bug Fixes
Latest Query Name Collisions
The fix enables users to choose whatever column names they would like inside of Latest
queries without generating errors.
Symptom
Seeing feature-level errors:
ValidationException: Invalid ProjectionExpression: Attribute name is a reserved keyword; reserved keyword: state
for features defined as Latest
queries, e.g.
state := Latest<user_responses>(state by zipcode)
Root Cause
Sumatra's implementation of Latest
left open the possibility of name conflicts with DynamoDB's list of reserved words, including "state".
Fix
Use Dynamo's expression attribute aliases to avoid the name collisions.
Spurious Divide By Zero Errors
The fix changes the behavior of the following aggregates to no longer generate errors when aggregating over the empty set:
Average
StdDev
Median
MedianAbsoluteDeviation
Symptom
Seeing feature-level errors:
avg_rate_per_zip: divide by zero
for features defined as Average
queries, e.g.
avg_rate_per_zip := Average(rate by zip)
and data where rate
is null
.
Root Cause
Sumatra's implementation of Average
and 3 other aggregates reported errors when missing data would result in a divide by zero. This error reporting is unnecessary as the null
return value is sufficient.
Fix
The design change was made to return null
without error for these 4 aggregates when aggregating over empty data.