Regular expression functions
The regular expression functions identify precise patterns of characters and are useful for data validation, for example, type checks, range checks, and checks for characters that are not allowed. The supported regular expression functions are fully Perl v5 compatible.
A description of how regular expressions operate is beyond the scope of this document. For information, see the many texts that describe how to construct Perl regular expressions.
- A match is found. The function returns the match value.
- A match is not found for the pattern at the current position; the function repeats the search process by using another part of the pattern.
There is a limit on the number of times that the function repeats execution with a new search pattern. In IBM® Netezza® SQL Extensions toolkit Release 1.3 and later, the limit is 10,000,000 recursions, which is the generally accepted default. (In prior releases, the default limit was 10,000.) If the limit is reached before a match is found, the function displays the error ERROR: 0 : Regex exec: Match limit reached, consider rewriting the pattern.
https?://([-\w\.]+)+(:\d+)?(/([\w/_\.]*(?\S+)))
https?://([-\w\.]+)(:\d+)?(/([\w/_\.]*(?\S+)))