Re: [GENERAL] 7.4Beta

Stephan Szabo wrote:

>I don't know if there will be or not, but in one case it's a single table
>select with constant values, in the other it's probably some kind of scan
>and subselect. I'm just not going to rule out the possibility, so we
>should profile it in large transactions with say 100k single inserts and
>see.
>  
>
You're talking about bulk operations, that should be handled carefully 
either. Usually loading all data into a temporary table, and making a 
INSERT INTO xxx SELECT FROM tmptable should give a better performance if 
indices and constraints are concerned. PostgreSQL shouldn't be 
considered to accept the most abusive ways of operation, but it should 
offer a reasonable set of tools enabling the jobs in a convenient way. 
Best situation available is if many small random transactions are 
performed good, for TPC like loads, as well as bulk operations. Nobody 
should expect that a database will smootly convert a bunch of single 
transactions into an optimized bulk one. That's the job of a programmer.

>Yeah, the 5 above are pretty easy to show that it's safe, but other cases
>and referential action cases won't necessarily be so easy.
>
So it's the programmers responsibility to offer mass data to the 
backend, not separate inserts that by chance might be handled in a 
similar way. A RDBMS is not a clairvoyant.

Regards,
Andreas