It seems as though apache/php are holding my connection open even though I am not using pconnect.  After every query "onstat" shows that there is still one lock.  If I try to add/delete an index Informix gives me the "hey, you don't have exclusive rights" error.  If I shutdown apache, then my add/delete works just fine.  If have tried this with a few combinations of unix/apache/php with the same results.  Those flavors are:

apache1.3.9/php3.0.12/sco5.0.5 odbc to itself,
same machine above odbc to sco5.0.0, and
apache1.3.6/php3.0.7/redhat6.2 odbc to both sco boxes

Both sco machines are running ods 7.12 and the redhat machine has SE.

In case you were wondering, the machine that has to odbc to itself is because I get informix error -27000 when connecting via php using shared memory.  Could be related.

I compiled php --with-informix. I don't think there is anything special about either of the installs.  The example below is more or less what I am using.

<?
putenv ("INFORMIXSERVER=dbs");
$conn_id = ifx_connect (database, "username", "password");
$res_id = ifx_prepare ('set isolation to dirty read', $conn_id);
ifx_do ($res_id);
$thestring = "select * from 'username'.table where field = '$some_input'";
eval ("\$thestring = \"$thestring\";");
$res_id = ifx_prepare ($thestring, $conn_id);
ifx_do ($res_id);
$row = ifx_fetch_row ($res_id, "NEXT");
ifx_free_result ($res_id);
ifx_close ($conn_id);
?>