MongoDB: the TTL sweep parses the stored number text as an integer, so a TTL value the native ADD pipeline writes as 1700000000.0 never expires #810

Summary

On MongoDB, the TTL sweep reads the stored text of the TTL number and parses it as a 64-bit integer. The native ADD pipeline writes the Decimal128 text of its sum, and with a fraction among the operands that text can end in .0. On MongoDB 7, 0.5 + 0.5 is written 1.0. By the same rule, 1699999999.5 + 0.5 is written 1700000000.0. GetItem returns 1700000000, because reads normalize a number, but the sweep cannot parse 1700000000.0 as an integer and skips the item.

Cause

Found by reading the code. The sweep was not run against such an item.

• crates/storage-mongodb/src/metadata_engine.rs:520 calls n_str.parse::<i64>() on the stored text for an attribute name without a dot.
• metadata_engine.rs:56 converts the stored text to long, with onError: null, for an attribute name that contains a dot.

main writes the same text: its native pipeline takes every number ADD. #803 keeps an ADD with a fraction on the native pipeline within its digit limits.

Fix shape

Parse the normalized text in the sweep (validate_and_normalize_number), and convert to decimal in the dotted-name query. DynamoDB's handling of a TTL value with a fraction was not measured, so the fix should keep today's handling of a value that is not an integer.