Re: [GENERAL] the best way to catch table modification

2005-10-26 Thread Janning Vygen
Am Dienstag, 25. Oktober 2005 19:40 schrieb David Gagnon:
 Hi,

   I posted on the same subject a month ago . .you can search for the
 current title in the JDBC mailing list
 [JDBC] implementing asynchronous notifications PLEASE CONFIRM MY

 I ended using statement-level trigger.  I haven't found another way to
 do it .

 Regards
 /David

 Marek Lewczuk wrote:
  Hello,
  I'm implementing db-queries caching system - for this I need to know
  each table's modification time (or at least modification counter). I
  know that I can make a statement-level trigger, which will update a
  table with tables modification times - however this is inefficient if
  many inserts or updates are made on single table (in single
  transaction). The best would be some kind of transaction-level
  trigger, but this is not available. Are there any other, better options ?

What did you mean with many inserts or updates? Did you mean statements 
which modify or insert many rows but are still one single statement: you 
could use rules instead. I think rules are much more powerful than triggers 
and they are much faster if a statement affects many rows. Triggers fires for 
each row, rules are just modifying the original statement. so usually if you 
can handle the load of the statements you should handle the loads of 
statements rewritten by rules, too. Rules are usually much more efficient 
than triggers. And they are much more relational in my opinion. 

kind regards,
janning




---(end of broadcast)---
TIP 1: if posting/reading through Usenet, please send an appropriate
   subscribe-nomail command to [EMAIL PROTECTED] so that your
   message can get through to the mailing list cleanly


Re: [GENERAL] the best way to catch table modification

2005-10-25 Thread David Gagnon

Hi,

 I posted on the same subject a month ago . .you can search for the 
current title in the JDBC mailing list

[JDBC] implementing asynchronous notifications PLEASE CONFIRM MY

I ended using statement-level trigger.  I haven't found another way to 
do it .


Regards
/David

Marek Lewczuk wrote:


Hello,
I'm implementing db-queries caching system - for this I need to know 
each table's modification time (or at least modification counter). I 
know that I can make a statement-level trigger, which will update a 
table with tables modification times - however this is inefficient if 
many inserts or updates are made on single table (in single 
transaction). The best would be some kind of transaction-level 
trigger, but this is not available. Are there any other, better options ?


Thanks in advance.
ML




---(end of broadcast)---
TIP 9: In versions below 8.0, the planner will ignore your desire to
  choose an index scan if your joining column's datatypes do not
  match




---(end of broadcast)---
TIP 4: Have you searched our list archives?

  http://archives.postgresql.org