eventsourcing/es4j

Problem: querying for aggregates is expensive

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#177 opened on Nov 6, 2016

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enhancementhelp wantedoptimization

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Description

Querying for things like:

  • latest (as in, biggest TIMESTAMP) event for a certain scope (say, reference=R1)
  • sum/avg/max/min for a certain scope (say, reference=R1)

is quite expensive as it involved a lot of scanning (as can be seen in https://github.com/eventsourcing/es4j/blob/master/eventsourcing-queries/src/main/java/com/eventsourcing/queries/IsLatestEntity.java and https://github.com/eventsourcing/es4j/blob/master/eventsourcing-queries/src/main/java/com/eventsourcing/queries/LatestAssociatedEntryQuery.java)

Proposed solution: designate and formalize an aggregate indexing system.

Contributor guide

Research direction
Review the current query implementations in IsLatestEntity.java and LatestAssociatedEntryQuery.java to understand the scanning issue, then design an aggregate indexing system to optimize aggregate queries.
Tech stack
java
Domain
backenddatabase
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaEvent Sourcing
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40