Michael Ho 34a94c2503 IMPALA-2404: Implements built-in function regexp_match_count ...

This patch implements a new built-in function
regexp_match_count. This function returns the number of
matching occurrences in input.

The regexp_match_count() function has the following syntax:

int = regexp_match_count(string input, string pattern)
int = regexp_match_count(string input, string pattern,
    int start_pos, string flags)

The input value specifies the string on which the regular
expression is processed.

The pattern value specifies the regular expression.

The start_pos value specifies the character position
at which to start the search for a match. It is set
to 1 by default if it's not specified.

The flags value (if specified) dictates the behavior of
the regular expression matcher:

m: Specifies that the input data might contain more than
one line so that the '^' and the '$' matches should take
that into account.

i: Specifies that the regex matcher is case insensitive.

c: Specifies that the regex matcher is case sensitive.

n: Specifies that the '.' character matches newlines.

By default, the flag value is set to 'c'. Note that the
flags are consistent with other existing built-in functions
(e.g. regexp_like) so certain flags in IBM netezza such as
's' are not supported to avoid confusion.

Change-Id: Ib33ece0448f78e6a60bf215640f11b5049e47bb5
Reviewed-on: http://gerrit.cloudera.org:8080/1248
Reviewed-by: Casey Ching <casey@cloudera.com>
Tested-by: Internal Jenkins

2015-10-27 10:11:13 +00:00

57 KiB

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