Slight incompatibility of error path of size() function in condition expression #14592
Labels
area/alternator
Alternator related Issues
Milestone
Comments
nyh
added a commit
to nyh/scylla
that referenced
this issue
Jul 9, 2023
The DynamoDB documentation for the size() function claims that it only works on paths (attribute names or references), but it actually works on constants from the query (e.g., ":val") as well. It turns out that Alternator supports this undocumented case already, but gets the error path wrong: Usually, when size() is calculated on the data, if the data has the wrong type of size() (e.g., an integer), the condition simply doesn't match. But if the value comes from the query - it should generate an error that the query is wrong - ValidationException. This patch fixes this case, and also adds tests for it that pass on both DynamoDB and Alternator (after this patch). Fixes scylladb#14592 Signed-off-by: Nadav Har'El <nyh@scylladb.com>
|
A minor, non-correctness improvement on the error path. Not backporting. |
MeepoYang
pushed a commit
to storage-scsg/scylladb
that referenced
this issue
Apr 28, 2024
The DynamoDB documentation for the size() function claims that it only works on paths (attribute names or references), but it actually works on constants from the query (e.g., ":val") as well. It turns out that Alternator supports this undocumented case already, but gets the error path wrong: Usually, when size() is calculated on the data, if the data has the wrong type of size() (e.g., an integer), the condition simply doesn't match. But if the value comes from the query - it should generate an error that the query is wrong - ValidationException. This patch fixes this case, and also adds tests for it that pass on both DynamoDB and Alternator (after this patch). Fixes scylladb#14592 Signed-off-by: Nadav Har'El <nyh@scylladb.com> Closes scylladb#14593
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
The DynamoDB documentation for the size() function in ConditionException claims that it requires a path parameter -
size(x)andsize(#xyz)work. If the data read from that path has a type that size() can't work on (e.g., an integer), the condition fails withConditionalCheckFailedException. So far so good, and Alternator behaves like DynamoDB in all these cases.But it turns out that DynamoDB also allows size's parameter to be a value instead of a path - i.e.,
size(:xyz)works even thought it's not documented. If the value:xyzdefined inExpressionAttributeValueshas a suitable type (e.g., a string) its size is defined and the condition using the size may pass. But if the value of:xyzhas the wrong type (e.g., an integer), DynamoDB knows the error is in the query itself - not the data - and generates aValidationException, with the error message:Invalid ConditionExpression: Incorrect operand type for operator or function; operator or function: size, operand type: N.Trying to use
size(size(x))also generates the sameValidationException- it's also a wrong type (size(x) is an integer, and size() can't be called on that) and known from the query - not from the data.The importance of this issue is very minor - it's only about the appropriate error type in a case that is in any case erroneous. Alternator also allows
size(:xyz)in cases where it's properly defined.The text was updated successfully, but these errors were encountered: