An SQL Descriptor Area (SQLDA) is a collection of parameters used only in dynamic SQL programs. SQL provides two descriptor areas: SQLDA and SQLDA2. Dynamic SQL lets programs accept or generate SQL statements at run time, in contrast to SQL statements that are part of the source code for precompiled programs or SQL module language procedures. Unlike precompiled SQL or SQL module language statements, such dynamically executed SQL statements are not necessarily part of a program's source code, but can be generated while the program is running. Dynamic SQL is useful when you cannot predict the type of SQL statement your program will need to process. To use an SQLDA, host languages must support pointer variables that provide indirect access to storage by storing the address of data instead of directly storing data in the variable. The languages supported by the SQL precompiler that also support pointer variables are PL/I, C, BASIC, and Ada. Any other language that supports pointer variables can use an SQLDA, but must call SQL module procedures containing SQL statements instead of embedding the SQL statements directly in source code. See the Oracle Rdb SQL Reference Manual for more detailed information.