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 <chucheng...@gmail.com> 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 >
