This file is the accurate, current record of every visual asset in this module: what exists, what it shows, and what was deliberately excluded. Nothing below is aspirational — if an asset is listed as built, it’s in the repository at the path shown; if it’s listed as excluded, the reason is stated rather than left implicit.
| File | Referenced in | Content |
|---|---|---|
index-scan-vs-table-scan.svg |
File 01 | Full table scan vs. index seek, side by side, with relative cost annotations |
btree-structure.svg |
File 02 | 3-level B+Tree — root, internal nodes, linked leaf nodes |
composite-index-order.svg |
File 03 | Nested physical sort order of a 3-column composite index |
leftmost-prefix-rule.svg |
File 03 | ✓/✗ checklist of query shapes against INDEX(a, b, c) |
clustered-vs-nonclustered.svg |
File 04 | Clustered (leaf = row) vs. non-clustered (leaf = pointer) comparison |
covering-index.svg |
File 05 | Non-covering (2 I/O) vs. covering (1 I/O) lookup comparison |
write-vs-read-tradeoff.svg |
File 06 | Read speed vs. write throughput as index count grows |
indexing-workflow.svg |
File 06 | OLTP vs. OLAP indexing decision flowchart |
index-selectivity.svg |
File 07 | Selectivity comparison: customer_id vs. status |
query-optimizer.svg |
File 07 | Cost-based optimization decision flow |
execution-plan.svg |
File 08 | Join plan tree with estimated-vs-actual row annotations |
index-lifecycle.svg |
File 10 | Healthy → degraded → maintained index lifecycle |
Three diagrams are inherently decision flows rather than structural
comparisons, so each also has a Mermaid source, embedded directly as a
collapsible <details> block immediately after its SVG in the
corresponding .md file (GitHub renders Mermaid natively — no image
load required):
query-optimizer.mmd → embedded in File 07execution-plan.mmd → embedded in File 08indexing-workflow.mmd → embedded in File 06The remaining 9 diagrams are structural/comparative rather than flow-shaped (B+Tree structure, side-by-side comparisons, bar-style selectivity charts) and are intentionally SVG-only — a Mermaid flowchart isn’t a natural fit for that content, and forcing one would produce a worse diagram, not a more complete asset set.
hero-banner.svg — README hero banner (B+Tree silhouette + module title)module-thumbnail.svg — small square icon for the handbook root README’s module tablesocial-preview.svg — 1280×640 GitHub Open Graph social preview cardAll three README-level assets specified for this module are complete.
Five PNG “screenshot-style” images were originally scoped
(ecommerce-indexes.png, banking-example.png, healthcare-example.png,
warehouse-schema.png, explain-output.png). These are not included,
and this is a deliberate decision, not an oversight: a generated image
styled to look like a real terminal/EXPLAIN capture would misrepresent
actual query output, which runs directly against this module’s own
accuracy standard. The correct path to these, if wanted, is to run the
corresponding .sql file against 00_SETUP.sql locally and capture a
real screenshot — every query that would appear in one of these images is
written and ready to run in Files 01, 06, 08, and 09.
All diagrams share one visual language, for anyone extending this set:
paper-white background with a faint grid (#FAFAF7 / #E8E4D9),
ink-navy linework (#1A1F2B), teal for the index/fast path (#147D7A),
amber for the scan/slow path (#C2410C), monospace labels (IBM Plex
Mono), sans-serif titles (IBM Plex Sans), and a corner-tick-mark
“blueprint” frame on every canvas. The README hero/social/thumbnail
assets use an inverted dark variant of the same palette
(#0B1420 background, #2DD4C7 accent) to read correctly as a banner
image rather than an in-page diagram.