**Long integers in Microsoft SQL Server and PostgreSQL are created with a precision of 10 and scale of 0. *Short integers in all other databases are created with a precision of 5 and scale of 0. Use this table to help you choose data type, precision, and scale: Data type On the other hand, if you specify a float with a precision of 5 and a scale of 3, the field allows you to enter 12.345, 12.34, or 12.3.ĭata types and their possible precision and scale values you can set in ArcGIS Desktop are listed in the following table. If you enter 12.345 in the field, an error message displays, as this exceeds the maximum number of digits and decimal places allowed. For example, if you specify a float with a precision of 4 and a scale of 2, the field accepts 12.34 (or 12.3 or 12). Specifying the precision and scale allows you to restrict the range of values and number formats a field can accept, giving you greater control. Long integers in IBM Db2, IBM Informix, or Oracle.Floats or doubles in a database or enterprise geodatabase.Exceptions are when you create one of the following fields: In most cases, you will not specify precision or scale when creating numeric fields in tables in a geodatabase. Numeric values with fractional values within specific rangeĭouble (double-precision floating-point number) Numeric values without fractional values within specific rangeįloat (single-precision floating-point number) Numeric values without fractional values within specific range coded values Ranges differ slightly in databases and enterprise, workgroup, and desktop geodatabases. The ranges listed are for file and personal geodatabases. The following table lists data types, their ranges, and storage requirements. If you need to store fractional numbers between -3.4E38 and 1.2E38 only, specify the float data type, because it takes up 4 bytes, whereas the double data type takes up 8. If you need to store integers between -32,768 and 32,767 only, specify the short integer data type, because it takes up only 2 bytes, whereas the long integer data type takes up 4. This not only minimizes the amount of storage required but also improves performance. Second, when choosing between a short or long integer or between a float or double, choose the data type that takes up the least storage space. If you need to store fractional numbers that have decimal places, such as 0.23 or 1234.5678, specify a float or a double. If you just need to store whole numbers, such as 12 or 12,345,678, specify a short or long integer. In choosing the data type, first consider the need for whole numbers versus fractional numbers. Double (double-precision floating-point numbers).Float (single-precision floating-point numbers).You can store numbers in one of four numeric data types: Be sure you know the data type and size limitations of your destination storage format when moving data between data storage types. To learn more about the data type mapping process with your database management system, see Data types in the DBMS.Īdditionally, other data storage formats, such as shapefiles or dbf tables, have different data type limitations. As a result, the data type you see in the table or feature class properties in ArcGIS Desktop may change from what you initially defined. In this process, it is possible that the values will be stored in the DBMS as a different type, applying different criteria to the data attribute. This process is referred to as data type mapping. The types are matched to the closest data type available. If you store your data in a database or a geodatabase in a database management system (DBMS), ArcGIS data types and the data types of the DBMS might not match exactly. The data types explained in this topic include the data types available when creating a feature class or table with ArcGIS. Choosing the correct data type allows you to correctly store the data and facilitates your analysis, data management, and business needs. The available types include a variety of number types, text types, date types, binary large objects (BLOBs), or globally unique identifiers (GUIDs). When you create feature classes and tables, you select a data type for each field.
0 Comments
Leave a Reply. |