Formulating an SQL query with missing FROM clauses will 
generate an apache segfault approximately 30% of the time 
it is executed, according to my tests. This *only* occurs 
with PostgreSQL > 7.1 in conjunction with php 4.0.6. 
Switching to older versions of either eliminates the 
bug,as does reformulating the SQL to contain the missing 
FROM clauses. When the crash occurs, PostgreSQL logs:

NOTICE:  Adding missing FROM-clause entry for table "bios"
pq_recvbuf: unexpected EOF on client connection 


SCRIPT:
-------

<?
$link=pg_connect("dbname dbuser dbpass");

$q="SELECT name FROM users WHERE users.bio_id = bios.id 
AND bios.id=1;

pg_exec($link,$q);
?>

SAMPLE TABLES:
--------------
CREATE TABLE users(char(20) name,int bio_id);
CREATE TABLE bios(id serial,char(20) name);


BACKTRACE:
----------
Program received signal SIGSEGV, Segmentation fault.
0x401d5f95 in shutdown_memory_manager (silent=1, 
clean_cache=0) at zend_alloc.c:449
449                                     
REMOVE_POINTER_FROM_LIST(ptr);
(gdb) bt
#0  0x401d5f95 in shutdown_memory_manager (silent=1, 
clean_cache=0) at zend_alloc.c:449
#1  0x40200515 in php_request_shutdown (dummy=0x0) at 
main.c:667
#2  0x401fdf93 in php_apache_request_shutdown (dummy=0x0) 
at mod_php4.c:292
#3  0x080682a0 in run_cleanups ()
#4  0x08066a81 in ap_clear_pool ()
#5  0x08066b06 in ap_destroy_pool ()
#6  0x08066a6e in ap_clear_pool ()
#7  0x08076ff8 in child_main ()
#8  0x080775e4 in make_child ()
#9  0x08077758 in startup_children ()
#10 0x08077dd7 in standalone_main ()
#11 0x0807860f in main ()
#12 0x4009b1f0 in __libc_start_main () from /lib/libc.so.6