Re: [GENERAL] Select for update Question

2003-12-10 Thread John Sidney-Woollett
> That may be because there is no guarantee of the ordering of your returned > records. That makes sense - I just didn't think of it. Doh! > Maybe you need to re-initialise your variables before executing the > select? I'm not sure what variables I could re-initialise here as the select statemen

Re: [GENERAL] Select for update Question

2003-12-10 Thread Paul Thomas
On 10/12/2003 09:10 John Sidney-Woollett wrote: [snip] Actually from my tests, the simple code below *sometimes* blocks on the locked row, and sometimes skips the locked row, and returns the next unlocked row. That may be because there is no guarantee of the ordering of your returned records. [s

Re: [GENERAL] Select for update Question

2003-12-09 Thread John Sidney-Woollett
> Unlikely as PostgreSQL doesn't support read uncommitted... You're right - Postgres only offers two levels "PostgreSQL offers the Read Committed and Serializable isolation levels." > I think you need to play with a couple of psql sessions to sort this out. > I think you might have a race conditi

Re: [GENERAL] Select for update Question

2003-12-09 Thread Paul Thomas
On 09/12/2003 11:47 John Sidney-Woollett wrote: Hi I have a function called from a java app (via jdbc) which identifies images awaiting processing. This is determined by checking the WPImageStateID field on the WPImageHeader record (1=awaiting, 2=being processed, 3=complete). The (jdbc) connection

[GENERAL] Select for update Question

2003-12-09 Thread John Sidney-Woollett
Hi I have a function called from a java app (via jdbc) which identifies images awaiting processing. This is determined by checking the WPImageStateID field on the WPImageHeader record (1=awaiting, 2=being processed, 3=complete). The (jdbc) connection to the database is a standard one so I suspect