Re: Matching unique primary keys
От | Shridhar Daithankar |
---|---|
Тема | Re: Matching unique primary keys |
Дата | |
Msg-id | 3DB8686C.14874.2711EA3@localhost обсуждение исходный текст |
Ответ на | Re: Matching unique primary keys (Kevin Old <kold@carolina.rr.com>) |
Список | pgsql-general |
On 23 Oct 2002 at 12:39, Kevin Old wrote: > 1) Copy the 3 "unique fields" into every table (as you mention above). > My only question with this is how am I to do a join on a multicolumn > primary key? The only thing I can think of would be something like: > > SELECT * > FROM data_index, data_tbl > WHERE data_index.id1 = data_tbl.id1 > AND data_index.id2 = data_tbl.id2 > AND data_index.id3 = data_tbl.id3 Well you can store the 3 fields in a table, declare the combination of them as primary key and add a fourth field that is sequence generated and use this sequence number as primary key in rest of them tables. Will reuce the IO requirement by oodles.. HTH Bye Shridhar -- ASCII: The control code for all beginning programmers and those who would become computer literate. Etymologically, the term has come down as a contraction of the often-repeated phrase "ascii and you shall receive." -- Robb Russon
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