[Bug]: Decimal Serialization in Collections Does Not Preserve Numeric Order

[TraderWithPython]

Is there an existing issue for this?

• I have searched the existing issues

What happened?

Issue Description

The current decimal serialization in Cosmos SDK does not preserve numeric ordering when used in Collections, which leads to incorrect iteration results. The issue arises because Collections sort decimals based on their string representation rather than their numeric values.

Current Behavior

The current implementation (

cosmos-sdk/math/dec.go

Line 426 in f9bb180

func (x Dec) Marshal() ([]byte, error) {

) serializes decimals into string format, causing incorrect ordering due to lexicographical comparison. For example:

• String "1E+5" is considered less than "2" because '1' < '2'
• However, numerically 1E+5 (100000) is greater than 2

This leads to counter-intuitive results when:

1. Iterating through Collections
2. Using Range queries
3. Maintaining sorted indexes

Expected Behavior

Collections should iterate through decimals in their true numeric order. For example:

• 1E+5 (100000) should be greater than 2
• -1 should be less than 2
• 1.23E+10 should be greater than 1.23E+9

Proposed Solution

Implement an order-preserving binary encoding for decimals:

Use IEEE 754-like binary encoding format which naturally preserves numeric ordering

Cosmos SDK Version

cosmossdk.io/math

How to reproduce?

No response