database-normalization

The first normal form says that row ordering should not matter. Does this mean that a table with date as part of the key is not 1NF? e.g. Consider a table of ticker prices where date/time is part of the PK. In this case, you get the last price by ordering the data by date and selecting the top 1 row. Does this mean that for to fulfill 1NF you need to split the table into: 1) TickerCurrentPrice (1 row per ticker) 2) TickerHistoricalPrice Thanks 1NF is aspect of a table representing a relation , not of a table as such. If your relation says ticket HAS price , that it's a 1NF violation, as you

I have a product table that contains two column ProductID Desc 1 Fan 2 Table 3 Bulb I have another table that contains supplier information SupplierID Desc 1 ABC 2 XYZ 3 HJK Now One supplier can supply multiple products and one product can be supplied by multiple suppliers To achieve this I have created another table tbl_Supplier_Product SupplierID ProductID 1 1 1 2 2 1 2 2 2 3 Is it a good way to link this table to supplier and product table through primary composite key. In this table the primary key would be a composite key (SupplierID and ProductID) or should I add an extra column row ID

So I am looking over my database notes and material trying to refresh myself on the general concepts and terminology for upcoming interviews. I have gotten stuck at dependency however and lossless-join decompositions though. I have searched all over and see lots of mathy equations but I am looking for a plain and simple English response or example. I have a found a powerpoint from http://www.cs.kent.edu/~jin/DM09Fall/lecture6.ppt which illustrates an example that I cannot fully understand. It is posted below. R = (A, B, C)F = {A → B, B → C) Can be decomposed in two different ways R1 = (A, B),

I'm interested in learning about tools that operate like this: Given a database schema and some data, suggest whether the schema is likely structured in any particular normal form, and then tell how the schema might be factored to produce further normalization. Basically, a static analysis tool for database schema design. Like other static analysis tools, such a database tool need not generate perfect results (I doubt such a "perfect" tool is computationally feasible), or applicable to all database systems, or free/open source, or anything else. The tool need not be stand-alone; it could be