CHAPTER 8Searching for Regular Expressions
As of Oracle Database 10g, the SUBSTR, INSTR, LIKE and REPLACE functions have been enhanced and extended to support searches for regular expressions. Regular expressions support a wide array of standardized controls and checks—for example, matching values a specific number of times, searches for punctuation characters, or searches for digits. You can use these new functions to perform advanced searches against strings. The new functions are named REGEXP_SUBSTR, REGEXP_INSTR, REGEXP_LIKE, and REGEXP_REPLACE.
Users who have previously used the UNIX grep command to search for regular expressions in text files may already be familiar with the concepts and search techniques involved.