Re: High-Profile Advocacy Opportunity: Vbulletin
От | Simon Riggs |
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Тема | Re: High-Profile Advocacy Opportunity: Vbulletin |
Дата | |
Msg-id | 1087938850.12015.31907.camel@stromboli обсуждение исходный текст |
Ответ на | Re: High-Profile Advocacy Opportunity: Vbulletin Forum (Alvaro Herrera <alvherre@dcc.uchile.cl>) |
Ответы |
Re: High-Profile Advocacy Opportunity: Vbulletin Forum
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Список | pgsql-advocacy |
On Tue, 2004-06-22 at 21:05, Alvaro Herrera wrote: > On Tue, Jun 22, 2004 at 08:51:07PM +0100, Simon Riggs wrote: > > > > Why is it better than COPY? > > > COPY is designed for bulk data loading from files etc. Extended INSERTs > > are used to minimise the number of round-trips to the database when > > issuing a few number of similar INSERTs, as when you do an > > Order/Order-Line (i.e. Master and many similar Details records). > > Huh? I think you should be able to issue a single multivalued insert to > a single table -- two queries in your Order/Order-Line example, not one. > Better explained, that would be: **If you're doing an Order/Order-Line insert you'll do 1 INSERT to Order and then multiple similar INSERTs to Order-Line: the multiple INSERTs into Order-Line are when you'd use the extended INSERT feature.** > You can do the same in Postgres issuing several commands separated with > semicolons. You can even use a single transaction by using BEGIN and > COMMIT at the start and end of the string. > > I think the real gain of multivalued insert will come from using batch > heap and index insertions, not roundtrip to the application. At least, > the roundtrip savings can be had with today's Postgres. > Yes, there are PostgreSQL ways of doing things, not my point, I was explaining the MySQL rationale as I saw it. > > On the technical side, I think we should have both extended INSERT and > > REPLACE on the TODO list... > > I don't think REPLACE is a good idea (useless non standard MySQL-ism). > MERGE and multivalued INSERT are. But they depend on someone actually > doing the work. Both are on the TODO list, I think. I think doing REPLACE is a trivial subset of MERGE, so should be easy enough to pull off once MERGE gets done. Regards, Simon Riggs
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