Coharyn Assess Change
Know what breaks before you change it.
Coharyn reconstructs system dependencies, business behaviour and evidence before a critical database or transformation change is made.
The problem
The dangerous part of ALTER TABLE is what you don't know depends on it.
Your schema is documented. Your dependencies aren't. A column feeds a view, the view feeds a procedure, the procedure feeds a nightly job in another system, and the people who wired it together left years ago. Before an engineer, DBA, migration team or transformation programme changes a database, Coharyn determines what may be affected and why, from evidence it has already gathered about how the systems actually behave.
- What reads this column, directly and transitively?
- Which validated business rules stop holding?
- Which cross-system process breaks at which boundary?
- Which reconciliation checks lose their basis?
- What is unknown, and how much of the picture is missing?
Supported inputs
Submit the change the way you already write it.
SQL / DDL
ALTER TABLE, DROP COLUMN, DROP TABLE, RENAME COLUMN, ALTER COLUMN, CREATE INDEX, DROP INDEX.
Migration script
Multiple ordered statements assessed as one change, in order.
Schema diff
Current schema versus target schema; every difference becomes an operation.
Git-style migration diff
A migration file diff where your toolchain produces one.
Manual object change
Table, column, action, described by hand when there is no script yet.
Statements are parsed with a dialect-aware SQL parser for PostgreSQL, Oracle, SQL Server and MySQL. Unknown or partially parsed syntax is never silently reinterpreted; it lowers confidence and is reported as an unknown.
Assessment pipeline
From change submission to evidence-backed assessment.
- 01Parse change
- 02Identify changed objects
- 03Query System DNA
- 04Traverse dependency graph
- 05Find invariants, processes, integrations, reconciliation rules
- 06Find historical evidence
- 07Calculate blast radius
- 08Calculate risk
- 09Generate validation plan
- 10Evidence-backed assessment
Risk levels
- LOWNothing validated depends on the object; evidence is complete.
- MODERATEDependencies exist but are covered by validation.
- HIGHValidated rules, processes or integrations are affected.
- CRITICALBusiness behaviour or cross-system processes break.
- UNKNOWNInsufficient evidence to determine safely. Coharyn says so rather than guessing.
UNKNOWN is mandatory. Absence of evidence is not evidence of absence; Coharyn never converts uncertainty into false confidence.
Risk dimensions, scored separately
Decisions Coharyn can recommend
Coharyn never executes production SQL. Assess Change is an intelligence and safety layer.
Example assessment
What an assessment looks like.
Synthetic demonstration estate Rendered from Coharyn's seeded synthetic telecom estate (CRM, Provisioning, Billing, Charging). Not a customer system; not a customer result.
ALTER TABLE SUBSCRIBER DROP COLUMN CUSTOMER_SEGMENT_ID;
Blast radius
- Direct dependencies7
- Inferred (transitive) dependencies14
- Business invariants5
- Processes3
- Connected systems2
- Integrations2
- Reconciliation rules2
- Unknown / unverified areas3
Potential business effects
- Discount eligibility
- Campaign segmentation
- Retention workflow
- Billing logic
- Product eligibility
Effects come from the seeded demo graph, not from presentation-time invention.
Required validation
- Dependency verification
- Downstream simulation
- Reconciliation rehearsal
- Rollback validation
WHY? Every item expands into Coharyn evidence.
VALIDATEDbilling.discount_rule references SUBSCRIBER.CUSTOMER_SEGMENT_ID
Structural evidence: view definition parsed; column referenced in 3 predicates. Validated against 292 subscriptions.
VALIDATEDInvariant: every ACTIVE subscriber has a non-null CUSTOMER_SEGMENT_ID
Statistical evidence: 0 violations over the full population at last run; compiled as a deterministic check.
INFERREDCRM campaign_selection joins on segment id without a declared foreign key
Value containment 99.3% of CRM rows matched; cardinality N:1; name similarity 0.95. Not yet confirmed by an owner.
VALIDATEDProcess: CRM Order Completed → Provisioning Success → Billing Offer Active
Temporal evidence: learned propagation window p99 × 1.5; segment id is a stage key in the retention branch.
OBSERVEDReconciliation rule: source segment counts must equal target segment counts
Reconciliation layer 'entity' depends on the column existing on both sides.
UNKNOWNCharging: no evidence either way for wallet allowance rules
Charging has no declared or discovered relationship to the segment id. Absence of evidence is not evidence of absence.
Knowledge states follow the Coharyn lifecycle: observed → inferred → validated → compiled. Inferred knowledge is never presented as proven truth.
Every assessment ships with a validation plan and a report.
Validation plan
- Pre-change checks
- Dependency verification
- Expected invariants
- Data validation queries
- Reconciliation queries
- Post-change checks
- Rollback prerequisites
- Recommended monitoring
Change Intelligence Report
Browser, print-ready, JSON and structured evidence export. Sections: executive summary, proposed change, risk, blast radius, system impact, business impact, evidence, unknowns, required validation, rollback readiness, recommendation, audit metadata. Suitable for a CTO, an architecture board, a change advisory board or a migration programme.
Every assessment is kept permanently, with its eventual outcome, so Coharyn learns from what actually happened after the change.
Assess a change
Bring the change you are worried about.
Assess Change runs on System DNA that Coharyn has learned from your real systems, read-only. The System Intelligence Pilot (USD 15,000, about four weeks) learns the affected system and assesses one proposed change with a full blast radius, validation plan and report. Describe the change below and we will scope it with you.
- Read-only credentials only
- Evidence behind every finding
- UNKNOWN reported honestly
- No production SQL executed by Coharyn
Request an assessment
Pre-selected: System Intelligence Pilot. Change the pilot if your situation is different.