Re: Fast reference without an index?
От | pgsql@mohawksoft.com |
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Тема | Re: Fast reference without an index? |
Дата | |
Msg-id | 16737.24.91.171.78.1107898174.squirrel@mail.mohawksoft.com обсуждение исходный текст |
Ответ на | Re: Fast reference without an index? (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Fast reference without an index?
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Список | pgsql-hackers |
> pgsql@mohawksoft.com writes: >> Is there a way, and if I'm being stupid please tell me, to use something >> like a row ID to reference a row in a PostgreSQL database? Allowing the >> database to find a specific row without using an index? > > ctid ... which changes on every update ... Well, how does an index do it? Say this: select * from mytable where name = 'foo'; The index must return something. Say I have a row that it constantly being updated, or has an original item inserted. An item which is valid within my transaction, and an item which has just be inserted but has a transaction id greater than mine. Dosn't the index have some base number which points to the first valid occurance of the row, and then the valid row is found based on the transaction ID, or has PG changed? Is that the ctid?
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