157 templates · page 2 of 2
Data & Schema diagram templates
ER diagrams, data flow, knowledge graphs, ontologies.
Railroad — CSV (RFC 4180)
Records, fields, and quoted fields with escaped double quotes.
Railroad / syntax diagramRailroad — ISO 8601 Date/Time
Calendar date with optional time, seconds, fraction, and timezone designator.
Railroad / syntax diagramRailroad — SQL SELECT
The reading path of a SELECT statement: columns, FROM, joins, WHERE, GROUP BY, ORDER BY.
Railroad / syntax diagramDFD — Student Records System
Enrolment to transcript in a student information system, separating the self-service portal from the system of record and showing that every transcript release writes the disclosure log the statutory return later reads.
Data flow diagramDFD — Retail Loyalty CDP
Retail customer data platform from till transaction to activated audience, tracing how the consent register gates the identifiers reaching the email and advertising vendors that sit outside the platform boundary.
Data flow diagramDFD — Clinical Trial Data Capture
Phase III electronic data capture from site eCRF to database lock, separating the identifiable site zone from the pseudonymised sponsor EDC and exposing the subject-key read that is the trial's re-identification path.
Data flow diagramI-MR Chart — API p95 Latency
Thirty fifteen-minute windows of p95 latency as individuals and moving range against a 250 ms SLO, where the deploy spike inflates the moving range and drives Cpk 2.23 apart from Ppk 1.46 — the gap between short-term and long-term spread.
Control chart (SPC)np Chart — Invoice Error Count
Twenty-four weeks of errors found in a constant audit sample of 200 invoices, plotted as counts rather than proportions, with binomial limits around np̄ = 8.79 and a rule-5 signal as the new billing rules bed in.
Control chart (SPC)Pareto — Mobile Crash Signatures
Crash groups for the first seven days of an Android release against the release before it, computing that 4 of 11 signatures cause 81.5% of 13,753 crashes and showing an image-cache OOM regression displacing the previous ANR at the top.
Pareto chartPareto — Clinical Trial Data Queries
Monitor-raised data queries by case-report-form field for a phase III study against the sponsor's previous one, computing that 5 of 13 fields generate 81.1% of 3,044 queries and that ECG capture entered the vital few this study.
Pareto chartLog Axis — Throughput Across Four Orders of Magnitude
Measured throughput against request size on a logarithmic y axis, with the axis stating its own base. A log axis is the right choice here and the wrong choice more often than it is used, so the template pairs it with a note saying what the reader has to do differently: on this axis equal vertical distances are equal RATIOS, not equal differences.
PlotTeaching Case — What a Log Axis Does With a Zero
A series containing a genuine zero plotted on a logarithmic axis, so the engine's sentence about it is visible next to the figure. Every plotting tool drops zero and negative values from a log axis; almost none says so, and the result is a series with a hole in it that a reader interprets as a series with no data there.
PlotAWS — Streaming Data Pipeline
Ingest to dashboard, with every edge carrying the kind of movement it really is: async where a stream sits between two services, data where bulk moves, request traffic only where something calls something. Reports clean. Drawing all three as one arrow is the commonest way an architecture diagram stops being useful.
Cloud architectureQueueing Network — Checkout API Call Chain
An 850-request-a-second checkout path across six services, where the payment adapter's bounded connection pool is the constraint and heavy-tailed pricing latency (cv 1.9) more than doubles the queue an M/M/c model would predict.
Queueing networkQueueing Network — CI Build Farm
Merge-queue pipeline at six jobs a minute with flaky-test retry loops from both suites, showing how a 90-slot integration executor pool, not the forty compile workers, is the station that touches the 80% target.
Queueing networkE-commerce Schema (ER)
Customers, orders, products, and line items as an ER diagram.
MermaidSaaS Multi-tenant Schema (DBML)
Tenants, users, and memberships for a multi-tenant SaaS.
DBMLKnowledge Graph — Ada Lovelace
Entities and typed relationships as a small knowledge graph.
Graphviz (DOT)Data Pipeline (ETL) — D2
Extract, transform, load with a warehouse and BI layer.
D2Library Management Schema (ER)
Members, books, copies, and loans.
MermaidBlog Schema (DBML) — Authors and Tags
Authors, posts, tags, and comments for a blog.
DBMLHospital Schema (ER)
Patients, doctors, appointments, and prescriptions.
MermaidInventory Schema (DBML) — Stock Movements
Warehouses, products, and stock levels.
DBMLSocial Network Schema (ER)
Users, posts, follows, and likes.
MermaidE-commerce ER Diagram
Customers, orders, line items and products.
MermaidBlog Schema (DBML) — Users and Comments
Users, posts, comments and a tag many-to-many.
DBMLLibrary Loans (ERD)
Members borrowing books via loans.
ERDData Pipeline (D2)
Ingest to lake to warehouse, feeding BI and ML.
D2E-commerce Schema (DBML)
Customers, orders, products and line items.
DBMLSchool Enrolments (ERD)
Students enrolling on courses.
ERDSales by Country (Choropleth)
A world map shaded by units sold.
Choropleth (GIS)Traffic to Conversions (Sankey)
Channels through landing pages to customers.
Sankey flowA/B Test Structure (Causal DAG)
Randomisation, variant, engagement and conversion.
Causal DAGCRM Schema (DBML)
Accounts, contacts, deals and activities.
DBMLHospital Appointments (ERD)
Patients, doctors and appointments.
ERDTraffic by Source (Pie)
Share of website traffic by channel.
MermaidInventory ER Diagram (Mermaid)
Warehouses, products, stock and suppliers.
MermaidInventory Schema (DBML) — Suppliers
Warehouses, products, suppliers and stock.
DBMLBanking Accounts (ERD)
Customers, accounts and transactions.
ERDIn-demand Tech Skills (Word Cloud)
Sized terms from a skills survey.
Word CloudDaily Orders (Calendar Heatmap)
Order volume by day with seasonal peaks.
Calendar HeatmapDFD — Smart Meter Half-Hourly Settlement
Level-1 flow of SMETS2 meter reads from the consumer premises through the regulated data network into supplier aggregation and industry settlement, with every boundary crossing drawn as attack surface.
Data flow diagramDFD — University Clearing and Enrolment
Level-1 data flow for a university clearing hotline through offer, enrolment and student loan notification, with the UCAS and Student Loans Company interfaces held outside the campus trust boundary.
Data flow diagramWord Cloud — Skills Named in 300 Data-Engineering Job Adverts
How many of 300 UK data-engineering job adverts name each skill: SQL appears in 268 and Python in 251, with orchestration (Airflow, dbt) and cloud warehouses close behind. Weights are adverts, not mentions, so no term can exceed 300. Illustrative values.
Word CloudFlame Graph — PostgreSQL Backend Running a Slow Report Query (perf)
perf samples from the one backend running a 41-second month-end revenue report (4,360 samples): 50.5% is a sequential scan feeding the hash join's build side, 18.8% of it waiting on reads from disk, and the sort that spills to temporary files costs a further 20%. Planning is 1.1% — the plan is the problem, not the planner. Illustrative values.
Flame GraphCollaborative edit with version conflict
Preserves local edits and makes concurrent changes visible before a merged save. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidDeletion request across dependent stores
Coordinates deletion receipts and explicit retention exceptions without inventing a universal retention deadline. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidDataset quality quarantine and release
Models corrected snapshots and withdrawal separately from initial validation. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidConsent capture, withdrawal and expiry
Treats purpose changes as requiring review and avoids equating silence with consent. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidOffline document synchronization states
Preserves dirty local content through transient failures and explicit conflict resolution. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidTenant membership and delegated authorization
Represents tenant-scoped membership, many-to-many permissions and attributable resource access. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidProcurement bids, evaluation and award audit
Retains evaluator declarations and bid-level scoring alongside final awards; uniqueness rules need database enforcement. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidData products, versions and transformation lineage
Models many-input transformations and immutable output versions with rule-level quality results. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidCompetency-aligned curriculum and assessment
Traces learning evidence from submissions through rubric criteria to program competencies. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
MermaidStreaming pipeline with quarantine and replay
Adds schema rejection, immutable capture, checkpoints and explicitly coordinated replay. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
Graphviz (DOT)Federated analytics with aggregate release review
Keeps record-level data at sites and makes output disclosure review an explicit release gate. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
Graphviz (DOT)Database migration rehearsal and rollback gate
Separates reversible routing from later schema retirement and requires backfill reconciliation. Original worked design example; adapt responsibilities, thresholds and assumptions to your system.
Mermaid