"Inverting" a table, OLAP-style
От | pacquet@newsguy.com |
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Тема | "Inverting" a table, OLAP-style |
Дата | |
Msg-id | 200209132318.QAA09972@newsguy.com обсуждение исходный текст |
Ответы |
Re: "Inverting" a table, OLAP-style
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Список | pgsql-sql |
I have a data-collection app, which creates a table like this, more or less: t timestamp name varchar value numeric the number of distinct values of <name> is 800 and growing, besides being data-dependent, so it might be pretty inconvenient to have a single table with 800 columns. (and we might exceed the 1600-column limit someday) But clients WOULD like to view the data sometimes as though it were: t x y z ---------------------------------------------------------------- t1 value when name='x' value when name='y' value when name='z' if they do a SELECT on time=t1 and (name='x' or name='y' or name='z') This seems like a fairly common desire. I know we could use Pivot Tables in Excel, or otherwise do it on the client, but the highest-leverage solution would be to present this abstraction in the server. Any ideas on how to do this?
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