Use static local variable instead of create it every calls.
Time cost of the new added unit benchmark test could reduce
from about 60 seconds to 10 seconds.
The parameter 'part' of parse_url function does not support lower case, and parse protocol not right.
And This function does not support parse 'port'.
This PR tries to make parse_url function case insensitive and support parse 'port'.
The issue: #4451
replace is an user defined function, which is to replace all old substrings with a new substring in a string, as follow:
mysql> select replace("http://www.baidu.com:9090", "9090", "");
+------------------------------------------------------+
| replace('http://www.baidu.com:9090', '9090', '') |
+------------------------------------------------------+
| http://www.baidu.com: |
+------------------------------------------------------+
