I recently submitted some PRs about Scalar functions, some of which have been merged and some are being reviewed, and some may be what you need.
Log2(x) :https://issues.apache.org/jira/browse/FLINK-9928 will be released in Flink 1.7exp(x): exists here https://ci.apache.org/projects/flink/flink-docs-stable/dev/table/sql.htmlregular express support: use similar to , also see here https://ci.apache.org/projects/flink/flink-docs-stable/dev/table/sql.html
regex extract : https://issues.apache.org/jira/browse/FLINK-9990 reviewingregex replace : https://issues.apache.org/jira/browse/FLINK-9991 reviewing
The status of most scalar functions can be seen here : https://issues.apache.org/jira/browse/FLINK-6810
徐涛 <firstname.lastname@example.org> 于2018年8月23日周四 下午3:16写道：
I found flink is lack of some basic functions , for example string split, regular express support, json parse and extract support, these function are used frequently in development , but they are not supported, use has to write UDF to support this.
And some of the provided functions are lack of usability, for example log(2, 1.0) and exp(1.0) with double params are not supported. I think they are not hard to implement and they are very basic functions.
Will flink enhance the basic functions , maybe in later releases?