{"id":309,"date":"2007-09-26T00:00:00","date_gmt":"2007-09-26T00:00:00","guid":{"rendered":"https:\/\/test.simple-talk.com\/uncategorized\/captain-codd-and-the-simple-proposition\/"},"modified":"2016-07-28T10:40:51","modified_gmt":"2016-07-28T10:40:51","slug":"captain-codd-and-the-simple-proposition","status":"publish","type":"post","link":"https:\/\/www.red-gate.com\/simple-talk\/opinion\/opinion-pieces\/captain-codd-and-the-simple-proposition\/","title":{"rendered":"Captain Codd and the Simple Proposition"},"content":{"rendered":"
\n

A pantomime for Database Professionals<\/h2>\n

Scene 1 <\/h3>\n

In the church vestry. Polly Morphism looks despairingly at Rev. D. Composition. The elderly priest is bent over his desk in a canonical form (he is a cardinal type). The candle flickers; Polly is tearful. <\/p>\n

\n
D Composition <\/dt>\n
(shaking his head sadly)<\/em> “Hah, that base Relvar! The wicked Relvar Predicate is entirely without any integrity constraints. He is an insensitive curser and a primitive operator. Do anything to avoid him,” <\/dd>\n
Polly: <\/dt>\n
“It is no good; he has my pet tuples in his nidalic view. I must retrieve them with my tuple extractor or they will be subject to lossy decomposition. I will have to bargain with him. <\/dd>\n
D Composition: <\/dt>\n
“I have to admit that he is a star schemer. You’ll have to negotiate, maybe offer buffer cash. Blackmail is rank Relvar’s characteristic function”. <\/dd>\n<\/dl>\n

Scene 2 <\/h3>\n

A smoky dive, called the ‘HotSpot ‘. Rough types abound. Relvar and Polly sit hunched over a table. Her faithful SPID stands behind her, arms folded impassively, scimitar tucked in his belt. Relvar’s SPID stands, sneering wickedly. <\/p>\n

\n
Polly <\/dt>\n
“I’ve come to negotiate, to make a simple proposition” <\/dd>\n
Relvar <\/dt>\n
“Your n-Place or mine? Your persistence is monadic. I’m glad you have seen reason, because your tuples are in my power. Soon, the Tuple Unwrapping will begin. Their internal predicates will be mine (Nasty laugh)<\/em>. I will be idempotent! <\/dd>\n
Polly <\/dt>\n
(flushing)<\/em> “You swine! Haven’t you heard of De Morgan’s Laws?” <\/dd>\n
Relvar <\/dt>\n
(with ACID sarcasm)<\/em> “Thanks for the Complement. You scare me! Hah! That flat relation? Pshaw!” (audience boos noisily)<\/em> <\/dd>\n
Polly <\/dt>\n
(thinks: Maybe this is a bad transaction scenario )<\/em> “Surely we can be sensible? I’m here to see if we can do a deal to retrieve my tuples. I have an atomic proposition that could lead to a Transaction. My SPID can start the process with a triggered procedure <\/dd>\n<\/dl>\n

(Suddenly, an Argument starts at a nearby base table. A fight breaks out. A lunging body falls perilously near to Polly and knocks her SPID flying. Inverted Tables everywhere. The scimitar skids across the floor. Quick as a flash, Relvar’s SPID leaps onto Polly’s SPID and pins him to the ground) <\/p>\n

\n
Relvar <\/dt>\n
(gloatingly)<\/em> “So fate has chosen your SPID to be a deadlock victim. Soon he will be a bound variable” <\/dd>\n<\/dl>\n

Captain Codd bursts in on the scene. A clash of Cymbals <\/p>\n

\n
Codd: <\/dt>\n
Not so fast, Relvar. You have committed a fatal error and made a hash of it. Polly is under my protection!! <\/dd>\n<\/dl>\n

(An immediate conflict ensues. Wham! Bam! Captain Codd delivers a lightning Sheffer stroke to Relvar’s jaw, Soon, Captain Codd has Relvar in a granular lock followed by a restriction, an immediate constraint, finishing with a deadly embrace) <\/p>\n

\n
Relvar <\/dt>\n
Aiee! You have me in a Multi-Relvar constraint. I repent!! Let me go! Release my constraint! From now on I shall lead a Normal life. <\/dd>\n
Captain Codd: <\/dt>\n
If so, it will be your first Normal Form, Relvar. I suspect you will need a unique constraint. Any base manipulation, and you will be a bound variable in a loop structure. <\/dd>\n
Polly <\/dt>\n
Thanks, Captain Codd! I rely on you but it is a multi-valued dependency, though I am irreducably dependent <\/dd>\n<\/dl>\n

Scene 3<\/h3>\n

An Arcadian meadow. The sun is shining. Polly Morphism and Captain Codd admire Polly’s flock of tuples <\/p>\n

\n
Polly <\/dt>\n
(surrounded by her bleating tuples, nuzzling up to her adoringly)<\/em> Oh Captain Codd, now my SPID is released and my tuples safe, I can enjoy a tuple union. How can I repay you? <\/dd>\n
Captain Codd <\/dt>\n
(looking serious)<\/em> It isn’t over until we can engineer some sort of total Relvar constraint, with an identity restriction. He could yet strike again. <\/dd>\n<\/dl>\n

Ominous music…<\/p>\n

Will Relvar Predicate strike again?
Look out for the thrilling Sequel to… Captain Codd and the Simple Proposition<\/strong> <\/p>\n

Heroic music…<\/p>\n

Ends.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

A Pantomime for Database Professionals.…<\/p>\n","protected":false},"author":154613,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[30],"tags":[4168,4144,4148],"coauthors":[],"class_list":["post-309","post","type-post","status-publish","format-standard","hentry","category-opinion-pieces","tag-database","tag-opinion","tag-opinion-pieces"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/posts\/309","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/users\/154613"}],"replies":[{"embeddable":true,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/comments?post=309"}],"version-history":[{"count":1,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/posts\/309\/revisions"}],"predecessor-version":[{"id":21006,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/posts\/309\/revisions\/21006"}],"wp:attachment":[{"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/media?parent=309"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/categories?post=309"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/tags?post=309"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.red-gate.com\/simple-talk\/wp-json\/wp\/v2\/coauthors?post=309"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}