Dear Ashish, Thanks for the comment. I found the following things from MySQL 6.0 ::
(1) Inside CREATE TABLE, TIMESTAMP does not have any format. It is treated like a primitive type (string). (2) Inside SELECT clause, TIMESTAMP(YYYYMMDDHHMMSS) is called as a routine with format information for output spec. =========== MySQL 6.0 function =============================== TIMESTAMP(expr), TIMESTAMP(expr1,expr2) With a single argument, this function returns the date or datetime expression expr as a datetime value. With two arguments, it adds the time expression expr2 to the date or datetime expression expr1 and returns the result as a datetime value. mysql> SELECT TIMESTAMP('2003-12-31'); -> '2003-12-31 00:00:00' mysql> SELECT TIMESTAMP('2003-12-31 12:00:00','12:00:00'); -> '2004-01-01 00:00:00' =============================================================== As a result, we have to define TIMESTAMP as primitive type as well as a complex type with format information. I have to upgrade the grammar after further inspection. I am going to add a basic design document to JIRA. Please provide suggestions. Thanks, Shyam --- On Mon, 3/9/09, Ashish Thusoo <athu...@facebook.com> wrote: > From: Ashish Thusoo <athu...@facebook.com> > Subject: RE: Please check grammar for TIMESTAMP > To: "hive-dev@hadoop.apache.org" <hive-dev@hadoop.apache.org> > Date: Monday, March 9, 2009, 2:52 PM > One immediate issue is that the format string is a lexical > token, so a string of that format will not conform to the > grammar at places where a string literal is expected. A > better approach is to treat the format as a stringliteral > and then do the format checks at the typecheck and semantic > analysis time. > > Ashish > > -----Original Message----- > From: Shyam Sarkar [mailto:shyam_sar...@yahoo.com] > Sent: Sunday, March 08, 2009 7:16 AM > To: hive-dev@hadoop.apache.org > Subject: Please check grammar for TIMESTAMP > > Hi Zheng and others, > > Could you please check Hive.g grammar changes for TIMESTAMP > (See the comments with // Change by Shyam)? > Please review and let me know your feedback. I shall write > a short design doc later for review after these short > exchanges. > > Thanks, > shyam_sar...@yahoo.com