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  1. MariaDB Connector/C
  2. CONC-372

Fix str_to_TIME() parsing wrt performance.

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • None
    • 3.0.8
    • None
    • None

    Description

      currently, parsing str_to_TIME() is too complicated, and even embarassing in terms of performance

      https://github.com/MariaDB/mariadb-connector-c/blob/6545b1d194d5fd037844f7a0d93604fb4757cf41/libmariadb/ma_stmt_codec.c#L199

      Following calls inside it can and should be removed.
      alloca, memcpy, memset, strchr (x4), sscanf

      Attachments

        Issue Links

          causes

          Bug - A problem which impairs or prevents the functions of the product. CONC-378 MYSQL_DATA_TRUNCATED not always returned by mysql_stmt_fetch() for numeric type

          • Major - Major loss of function.
          • Closed

          Activity

            wlad Vladislav Vaintroub added a comment - - edited

            while testing , found additional bugs in current str_to_TIME()

            Major :

            • "0000-00-00" after parsing becomes year 1970, should be 0
            • "0069-12-31" parses as year 1969, should be 69 (YYYY format)
              the above 2 make it impossible to parse anything from years 1 AD - 70 AD (and the fake MySQLish year 0)
            • "69-12-31" parses as year 1969, should be 2069

            Minor /debatable , differences with server

            • fails to parse "10:15:01." as TIME (note the trailing dot)
            • parses "10000-01-01", which server dismisses as incorrect date ( year > 9999)
            • parses time >= 839:00:00 and time <= -839:00:00, which server does not do
            • parses incorrect datetime "1999-12-31 834:59:59.999999" is parses as datetime, with hour = 834
            • server allows trailing spaces after values, but nothing else, str_to_TIME() allows anything ,except trailing dot e.g "2000-01-01a"
            • does not parse some formats that server can, e.g "YYYYMMDD"

            Server testing is done with SELECT TIME 'string' , SELECT DATE 'string', SELECT TIMESTAMP 'string' e.g

            select DATETIME '1999-12-31 834:59:59.999999';

            wlad Vladislav Vaintroub added a comment - - edited while testing , found additional bugs in current str_to_TIME() Major : "0000-00-00" after parsing becomes year 1970, should be 0 "0069-12-31" parses as year 1969, should be 69 (YYYY format) the above 2 make it impossible to parse anything from years 1 AD - 70 AD (and the fake MySQLish year 0) "69-12-31" parses as year 1969, should be 2069 Minor /debatable , differences with server fails to parse "10:15:01." as TIME (note the trailing dot) parses "10000-01-01", which server dismisses as incorrect date ( year > 9999) parses time >= 839:00:00 and time <= -839:00:00, which server does not do parses incorrect datetime "1999-12-31 834:59:59.999999" is parses as datetime, with hour = 834 server allows trailing spaces after values, but nothing else, str_to_TIME() allows anything ,except trailing dot e.g "2000-01-01a" does not parse some formats that server can, e.g "YYYYMMDD" Server testing is done with SELECT TIME 'string' , SELECT DATE 'string', SELECT TIMESTAMP 'string' e.g select DATETIME '1999-12-31 834:59:59.999999' ;

            People

              wlad Vladislav Vaintroub
              wlad Vladislav Vaintroub
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              Dates

                Created:
                Updated:
                Resolved:

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