Damir Sudarevic
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 Aug 4 awarded Caucus Aug 4 awarded Constituent Dec 9 comment Normalized database table with non-atomic values If the domain is `customer comment` than trying to insert more than one is not atomic. Google "What First Normal Form Really Means". You have to understand the concept of domain. Dec 9 comment Normalized database table with non-atomic values Yes, sentence -- any text can be considered "atomic". The domain of that column is `customer comment`-- set of all possible customer comments.So, each row-column intersection contains exactly one customer comment. Sep 25 answered Architecting table with multiple paths to common parent tables Aug 15 answered Should I add transitive foreign keys? Aug 13 comment Identifying functional dependencies If {A} -> {C} holds, then {A,+} -> {C} holds too. IF {C} -> {A} holds then {C,+} -> A holds too; therefore {C,D} -> {A} is true. Same logic for {B,C} -> E and {B,C,A} -> E. Not sure which book you have, but there are many bad DB books out there... in other words throw this one to garbage and get some classics. Jun 24 awarded Yearling May 16 answered Rules for Decomposition to 2 NF May 15 comment Rules for Decomposition to 2 NF Simple, you do not stop before BCNF -- why would you? May 15 comment Rules for Decomposition to 2 NF If the table is in 3NF then it is also in 2NF and 1NF. Your decomposition algorithm should take you to BCNF. Apr 22 comment How to convert this relation to 2NF? ... [cont] And if the rule states that all clases do have the same duration, and that can not change, then you can simply drop the `CEndTime` column. Apr 22 comment How to convert this relation to 2NF? No, the partial dependency does not exists -- you are interpreting your current data where all classes have the same duration; however, given that a class may have any duration that conclusion is not valid. When defining FD you must focus on the business rule and all possible legal data values, not the current set of values. Apr 17 revised Advanced design question related to compound primary keys added 11 characters in body Apr 17 revised Advanced design question related to compound primary keys added 7 characters in body Apr 17 answered Advanced design question related to compound primary keys Apr 7 comment Does redundancy exists in this table? @Jose_Sunstrider; well still flawed; left a comment on the article there. Apr 6 comment Does redundancy exists in this table? Where did you find that definition? It is flawed -- think `UserID` appearing in multiple tables. Oct 31 comment If all variables are a subset of the candidate key, is the database design 5NF? @Lukazoid -- study that link before providing data and rules. That example contains a table and dataset that can be considered BCNF or 6NF just by stating a business rule -- same table same data. Oct 31 revised If all variables are a subset of the candidate key, is the database design 5NF? added 25 characters in body