PEAR DB seems to block 2nd connection from same browser (or CLI execution)

Hi all, My first post here (in 4 years or so ;)) so I guess a quick intro is in place; I've been developing PHP since 1998 or so, and used MySQL or PostgreSQL as the backend DB. I've also worked a lot with extensions such as ImageMagick, GD, DOMXML, Sablotron, etc. Anyway.... We've just discovered a peculiar behaviour from our scripts. It started out with us noticing that our back-end CLI scripts weren't running asynchronously, but instead they ran consecutively. It turned out that the 1st script was running just fine, while the 2nd script was waiting to access the database. (PostgreSQL via PEAR DB, using the same DSN). I've since created a test case to narrow down our "discovery". I've created a simple table, something like this: CREATE TABLE test_concurrency ( concurrency_id serial primary key NOT NULL, one integer, two integer, created timestamp DEFAULT now() NOT NULL ); I've then created a frameset that holds two pages; scripts "One" and "Two". Script "One" will update column 'one' in the aforementioned DB with 1, something like UPDATE test_concurrency SET one = (one + 1). Script "Two" does the same thing, but on column 'two'. Script "One" runs for a longer time (say 800 iterations), and has got a slight delay in the loop (usleep(10000);), and script "Two" runs for a shorter time, say 200 iterations. In the loop both scripts also query the same table to output the values of the row, both columns 'one' and 'two' (referred to C1 and C2 later in the post). Before entering the loop, the scripts reset their "own" column to 0. Using PEAR DB, I start "One" (reload the frame), and then almost immediately after I start "Two"... The result is that is that "One" reports C1 starting at 1 and finishing at 800, while C2 stays at 200. When "One" finishes, "Two" starts, reporting C1 at 800, and C2 from 1 to 200. There's one exception to this, and that seems to be when opening a new browser window and pasting the URI to the frameset into this; upon when the scripts display the behaviour I'll explain below. Reloading the frameset displays the aforementioned behaviour. If I use native PostgreSQL functions, I get the behaviour that I'm looking for and expecting; Starting "One" and then quickly starting "Two" results in "One" displaying C1 starting at 1 going up to 800, while C2 starts at 200, and at some point resets to 1, and increments to finish at 200, to stay there. "Two" displays C1 starting at an arbitrary number between 1 and 800, and finishes ca +200 later. C2 displays 1 to 200. This indicates that while "One" was running "Two" was able to access the same table and manipulate it. This is what we like! :) We've tried various things, such as adding $aDSN['new_link'] = TRUE; to the options for DB::connect($aDSN); Can anyone explain the behaviour we're getting with PEAR DB, and if there's some way to turn it off as we need to be able to run several CLI scripts simultaneously. We really don't want to track back to 1997 and write our own PostgreSQL wrapper - that'd feel a bit wrong. If required I can tidy up the scripts and post them somewhere for you to try. Any comments and ideas appreciated! Thanks! /Jocke