Ask Tom: On ROWNUM and Limiting Results. Regular Expressions in Oracle Database 10g (Continued) Using Regular Expressions in Oracle Database. This chapter introduces regular expression support for Oracle Database. This chapter covers the following topics: Using Regular Expressions with Oracle Database: Overview This section contains the following topics: What Are Regular Expressions? Regular expressions enable you to search for patterns in string data by using standardized syntax conventions. You specify a regular expression by means of the following types of characters: Metacharacters, which are operators that specify search algorithmsLiterals, which are the characters for which you are searching A regular expression can specify complex patterns of character sequences.
(f|ht)tps? The parentheses are metacharacters that group a series of pattern elements to a single element; the pipe symbol (|) matches one of the alternatives in the group. How Are Oracle Database Regular Expressions Useful? Regular expressions are a powerful text processing component of programming languages such as Perl and Java. Note: Oracle Regular Expressions. Regular Expressions in Oracle Database 10g.