mysqlnd read-only copy-on-write memory savings

gistfile1.txt

julien@lapjpauli:/tmp$ valgrind /home/julien/php53mysqlnd/bin/php -dmemory_limit=-1 /home/julien/www/mysqlnd_POC/poc_mysqlnd.php 1000
initial memory ->86480 kB
resultSet stored ->229632 kB
query result saved ->234016 kB
query result freed ->234016 kB
resultSet freed ->134816 kB
Db closed ->134816 kB
==32226== 
==32226== HEAP SUMMARY:
==32226==     in use at exit: 0 bytes in 0 blocks
==32226==   total heap usage: 15,799 allocs, 15,799 frees, 120,705,322 bytes allocated
==32226== 
==32226== All heap blocks were freed -- no leaks are possible
==32226== 
==32226== For counts of detected and suppressed errors, rerun with: -v
==32226== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)

julien@lapjpauli:/tmp$ valgrind /home/julien/php53libmysql/bin/php -dmemory_limit=-1 /home/julien/www/mysqlnd_POC/poc_mysqlnd.php 1000
initial memory ->88768 kB
resultSet stored ->245104 kB
query result saved ->414804 kB
query result freed ->336628 kB
resultSet freed ->198228 kB
Db closed ->193924 kB
==32241== 
==32241== HEAP SUMMARY:
==32241==     in use at exit: 0 bytes in 0 blocks
==32241==   total heap usage: 14,452 allocs, 14,452 frees, 260,903,720 bytes allocated
==32241== 
==32241== All heap blocks were freed -- no leaks are possible
==32241== 
==32241== For counts of detected and suppressed errors, rerun with: -v
==32241== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)