Hi Ran Tao, It sounds reasonable,and what is the maximum precision in Postgresql? Best, LakeShen
Ran Tao <[email protected]> 于2023年8月7日周一 11:38写道： > sorry for the reference link. > > engine precision range scale range > calcite [1,19] [1,19] > oracle[1] [1,38] [-84,127] > sqlserver[2] [1,38] [0,38] > mysql[3] [1,65] [0,30] > spark[4] [1,38] [0,38] > hive[5] [1,38] [0,38] > flink[6] [1,38] [0,38] > > > Ran Tao <[email protected]> 于2023年8月7日周一 10:58写道： > > > Hi, devs. I have noticed that currently calcite default maximum precision > > and scale is 19. > > If we set Decimal(50,2), it will reduce to Decimal(19,2). > > while other mature database systems or bigdata engines have more bigger > > value. > > > > For consistency and to give calcite users a standard value that meets > most > > engines, can we adjust the value of calcite to 38? > > > > Besides, the sql standard defines the meaning of precision and scale, > > letting each system customize the maximum precision and scale. (sql1999, > > page 125) > > > > engine precision range scale range > > calcite [1,19] [1,19] > > oracle [1,38] [-84,127] > > sqlserver [1,38] [0,38] > > mysql [1,65] [0,30] > > spark [1,38] [0,38] > > hive [1,38] [0,38] > > flink [1,38] [0,38] > > We can see many systems or engines follow the sql standard to make > maximum > > precision and scale to be 38, except oracle and mysql. > > > > If anyone can share some history or reasons why calcite set 19, i will > > appreciate it. > > > > [1] > > > https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlqr/Data-Types.html#GUID-DCCC6F18-15A0-4ECC-BA48-16F73F844844 > > > > [2] > > > https://learn.microsoft.com/en-us/sql/t-sql/data-types/decimal-and-numeric-transact-sql?view=sql-server-ver15 > > > > [3] > > > https://dev.mysql.com/doc/refman/8.0/en/precision-math-decimal-characteristics.html > > > > [4] > > > https://spark.apache.org/docs/3.2.0/api/java/org/apache/spark/sql/types/DecimalType.html > > > > [5] > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=82706456#LanguageManualTypes-decimal > > > > [6] > > > https://nightlies.apache.org/flink/flink-docs-master/api/java/org/apache/flink/table/api/DataTypes.html > > > > > > Best Regards, > > Ran Tao > > https://github.com/chucheng92 > > >
