calling odbc_free_memory frequently causes a delay of 0.3 secs when using ibm db2 udb v7.1 (FP2)
when i do not use odbc_free_memory between calls of odbc_exec, then submitting the query takes about 0.3 secs longer or returning from a function which called odbc_exec causes the delay.

the time delay seems to be dependent on system memory, because with 384MB (and a single processor system) it is much less then with 1GB (and a dual processor system)

the same application using a mysql-database (which is identically to the db2-database) does not suffer any performance problems (and takes some 1/100 secs for the same queries), so i think the problem may be in the unified odbc-functions.
maybe this is related to the memory leak problem reported before, but i thought this should be solved in 4.0.6

i applied the limit-memory-patch and configured php-4.0.6 with:
./configure '--enable-safe-mode' '--enable-sysvsem' '--enable-sysvshm' '--enable-trans-sid' '--enable-magic-quotes' '--enable-memory-limit' '--with-ttf' '--with-imap' '--with-gd=yes' '--enable-yp' '--with-jpeg-dir=/usr' '--with-tiff-dir=/usr' '--with-config-file-path=/etc/httpd' '--with-apxs=/usr/sbin/apxs -ltiff -lnsl -lpdf -ljpeg' '--with-exec-dir=/usr/lib/apache/bin' --with-openssl --with-mcrypt '--with-ibm-db2=/home/db2inst1/sqllib' --disable-debug

additionally i use a compiled version of the php-scripts, with the zend optimizer 1.1.0, but without compiling the scripts, the problem still persists.