Re: Maximum of Columns in one table (9i)

Connor McDonald <connor_mcdonald_at_yahoo.com> wrote:

>I have a stack of people each of which provide a Y or N response to 200
>questions, after which the table is static.

>So I could have:
>person,question_no,response

Nice, neat 3 column table!

>or
>person,q1response,q2response,....,q200response

A not so nice, not so neat 201 column table.

>Yep, I know the former is far more elegant,correct,<insert favourable
>term here>, but if my requirement is to be able to query any permutation
>of responses, eg "all the people that answered Y to question 17 or N to
>questions 12,31,65,197 or ....", then the latter (with some bitmap
>indexes) is probably gonna fly a lot better.

OK, at the risk of further exposing my ignorance here, what would be the difference (in particular for the sort of query you mention, and it's a good example) between having your 201 column table or having a table with 1 column which was an array with 201 elements.

How would this effect the querying you mentioned? I generally abhor arrays in dbs anyway, but just from a theoretical perspective.

>Sometimes the limitations/features of the target environment will make
>deviate from "whats right"

Pity that the OP seems to have dropped the thread and is not providing any explanation as to why he wants a truckload of columns.

Paul...

>Connor

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