Window Functions for Blockchain Activity Analysis
Use SQL window functions for running totals and ordered comparisons while preserving event grain, exact quantities and deterministic ordering.
Overview
When translating these concepts into an integration, keep the scope described by the wallet history api with the result. The examples in wallet transaction history and smart contract event logs show how the same distinction affects neighbouring data questions.
Window functions can add analytical context without collapsing each event into one aggregate row. Their ordering and frame rules need to match the blockchain evidence model.
Specify partition, order and frame
Partition by the appropriate wallet, asset and network identity. Order by accepted block and execution positions rather than timestamp alone. An explicit row frame can differ from a peer-based default when several rows share the same ordering value. Choose exact numeric storage for large quantities.
Worked example: equal timestamps
Two token movements share a block timestamp: plus five and minus two. A running total ordered only by timestamp can group peers or vary their sequence depending on the query. Adding stable event positions and a declared frame makes the displayed progression reproducible for the accepted evidence.
Keep opening state explicit
A running movement sum is not automatically an absolute wallet balance. It needs a justified opening balance and complete relevant changes. Test partial ranges, null amounts and reorganised events. If the evidence starts halfway through history, label the result as cumulative movement within the range instead of a lifetime balance.
A practical acceptance test
Give equal-timestamp events distinct execution positions and compare an explicit row frame with the engine’s relevant default. Assert a stable running movement total under the chosen query. Then remove opening state and verify that the output remains labelled cumulative movement, not an absolute historical balance. Missing history must not be replaced with an assumed zero opening.
Questions about the topic
Frequently asked questions
Does a running transfer sum always equal balance?
No. Opening state and complete balance-change evidence are required.
Is timestamp alone a stable window order?
No. Add deterministic execution tie-breakers.
Standards & technical documentation
