Re: [HACKERS] Please advise features in 7.1 (SUMMARY)
At 05:24 AM 11/30/00 +, Thomas Lockhart wrote: Is "if" clause support in PG? for example: "drop table aa if exist" "insert into aa values(1) if not exists select * from aa where i=1" No. afaict it is not in any SQL standard, so is unlikely to get much attention from developers. The insert, at least, can be written in standard SQL anyway... - Don Baccus, Portland OR [EMAIL PROTECTED] Nature photos, on-line guides, Pacific Northwest Rare Bird Alert Service and other goodies at http://donb.photo.net.
AW: [HACKERS] Please advise features in 7.1 (SUMMARY)
This is a summary of replies. 1. Calculated fields in table definitions . eg. Create table test ( A Integer, B integer, the_sum As (A+B), ); This functionality can be achieved through the use of views. Using a view for this isn't quite the same functionality as a computed field, from what I understand, since the calculation will be done at SELECT time, rather than INSERT/UPDATE. I would expect the calculated field from above example to be calculated during select time also, no ? You don't want to waste disk space with something you can easily compute at runtime. Andreas
Re: [HACKERS] Please advise features in 7.1 (SUMMARY)
I guess it depends on what you're using it for -- disk space is cheap and abundant anymore, I can see some advantages of having it computed only once rather than X times, where X is the number of SELECTs as that could get costly on really high traffic servers.. Costly not so much for simple computations like that but more complex ones. Just playing the devil's advocate a bit. -Mitch - Original Message - From: "Zeugswetter Andreas SB" [EMAIL PROTECTED] To: "'Ross J. Reedstrom'" [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Tuesday, November 28, 2000 7:50 AM Subject: AW: [HACKERS] Please advise features in 7.1 (SUMMARY) This is a summary of replies. 1. Calculated fields in table definitions . eg. Create table test ( A Integer, B integer, the_sum As (A+B), ); This functionality can be achieved through the use of views. Using a view for this isn't quite the same functionality as a computed field, from what I understand, since the calculation will be done at SELECT time, rather than INSERT/UPDATE. I would expect the calculated field from above example to be calculated during select time also, no ? You don't want to waste disk space with something you can easily compute at runtime. Andreas
Re: [HACKERS] Please advise features in 7.1 (SUMMARY)
So, having _both_ is the best thing. Absolutely, that's always what I meant -- we already have views and views can do this type of stuff at SELECT time can't they? So it's not a change, just an addition -Mitch
[HACKERS] Please advise features in 7.1 (SUMMARY)
Thanks for your help, everyone. This is a summary of replies. 1. Calculated fields in table definitions . eg. Create table test ( A Integer, B integer, the_sum As (A+B), ); This functionality can be achieved through the use of views. Implementing the create table syntax may not be too hard, but not in 7.1... 2 Parameterised Triggers Functionality is there, just that the documentation gave the wrong implication. An user manual example of using parameterised triggers to implement referential integrity would be welcome. 3. Stored Procedures returning a record set. Dream on! Regards John
Re: [HACKERS] Please advise features in 7.1 (SUMMARY)
On Tue, 28 Nov 2000, John Huttley wrote: 3. Stored Procedures returning a record set. Dream on! This is something I would be really interested to see working. What are the issues? my understanding is that it is technically feasible but too complicated to add to PL/PGsql? it seems to me a basic service that needs to be implemented soon, even if its just returning multiple rows of one column... - Andrew
