Stage 6

Design the physical data model

Designs a physical data model for the target platform without introducing anomalies

42 knobits (12 knowledge, 30 skills) · Produces: physical model · Builds on: Derive the logical data model

Knobit map

Each mark is one knobit. Knobits higher up build on the ones below them; select one to open it.

Circle: skill
Square: knowledge

Knobits of this stage

Knobit		Type
K-601	Recognises an unmanaged duplicate column	Skill
K-602	Recognises logical entities merged into one table	Skill
K-603	Recognises a stored derived or summary value	Skill
K-604	Recognises a lossy or unconstrained vertical split	Skill
K-605	Recognises an entity split into clone tables by value	Skill
K-606	Recognises rolled-up subtypes losing conditional constraints	Skill
K-607	Recognises rolled-down subtypes losing supertype constraints	Skill
K-608	Recognises a hierarchy encoded redundantly	Skill
K-609	Recognises content held outside the database by reference	Skill
K-610	Recognises a surrogate key without natural-key uniqueness	Skill
K-611	Recognises a surrogate value with meaning, reused or renumbered	Skill
K-612	Recognises an undeclared foreign key	Skill
K-613	Recognises a referential action destroying what should survive	Skill
K-310	Recognises a constraint claimed by a rule and missing from the schema	Skill
K-313	Recognises a declared constraint the target platform does not enforce	Skill
K-616	Recognises a changeable value list fixed in the DDL	Skill
K-617	Recognises a physical domain differing from the logical domain	Skill
K-618	Recognises binary floating point used for an exact quantity	Skill
K-629	Recognises a sentinel value standing in for null	Skill
K-630	Recognises a null with a business meaning	Skill
K-620	Recognises a business fact held in physical row order	Skill
K-621	Recognises an index set not derived from access paths	Skill
K-622	Recognises an overwrite where history is required	Skill
K-623	Recognises inconsistent validity periods in a versioned table	Skill
K-624	Recognises a reference to a versioned table by business key alone	Skill
K-625	Recognises a soft delete the constraints do not understand	Skill
K-626	Recognises a fact table of mixed grain	Skill
K-627	Recognises a measure without stated additivity	Skill
K-628	Recognises a nullable foreign key on a reporting join path	Skill
K-651	Explains controlled denormalisation	Knowledge
K-652	Explains the implementation options for subtypes	Knowledge
K-653	Explains referential integrity and referential actions	Knowledge
K-654	Explains exact and approximate numeric types	Knowledge
K-655	Explains null semantics and three-valued logic	Knowledge
K-656	Explains value sets held as reference data	Knowledge
K-657	Explains index design from access paths	Knowledge
K-658	Explains history strategies and validity-period conventions	Knowledge
K-659	Explains grain and additivity in dimensional models	Knowledge
K-660	Explains vertical and horizontal partitioning of tables	Knowledge
K-661	Explains consistency of content stored by reference	Knowledge
K-662	Explains the absence of row order in relational tables	Knowledge
K-641	Routes a defect to the deliverable responsible for it	Skill