Dynamic function invocation
According to an example, dynamic function invocation may include ascertaining a query for a database management system (DBMS). Dynamic function invocation may further include implementing a dynamic function as a meta user defined function to invoke a plurality of different coded functions including a coded function that is to be invoked by the query to perform an operation related to the DBMS, and executing the dynamic function by the query to load and invoke the coded function to perform the operation related to the DBMS.
1. A method comprising:
ascertaining a query for a database management system (DBMS), wherein the query comprises a dynamic function corresponding to a plurality of coded functions, each coded function of the plurality of coded functions comprises a DBMS unwrapped coded function, and each coded function of the plurality of coded functions is unregistered with a query execution engine of the DBMS; and
executing, by a processor, the query, wherein the executing comprises the query execution engine loading a given coded function of the plurality of coded functions identified by the dynamic function from a library external to the DBMS and invoking the given coded function to perform an operation related to the DBMS.
2. The method of claim 1 , wherein the given coded function comprises a Java function.
3. The method of claim 1 , wherein the query comprises a Structured Query Language (SQL) query.
4. The method of claim 1 , wherein the given coded function is generated by a user to perform an operation on a variable.
5. The method of claim 1 , wherein the library comprises a library of coded functions that are to perform operations on variables.
6. The method of claim 1 , wherein the given coded function is generated without using any system calls of the DBMS.
7. The method of claim 1 , wherein the executing comprises accessing a library name specified by the query.
8. The method of claim 1 , wherein the executing comprises:
accessing a class that includes the given coded function by a class name; and
accessing the given coded function by a function name from the class that includes the given coded function.
9. The method of claim 8 , wherein the executing comprises:
converting the class name to a class object instance; and
converting the function name to a function object instance.
10. An apparatus comprising:
a processor; and
a memory storing machine readable instructions that, when executed by the processor, cause the processor to:
ascertain a query for a database management system (DBMS), wherein the query comprises a dynamic function corresponding to a plurality of coded functions, each coded function of the plurality of coded functions comprises a DBMS unwrapped coded function, and each coded function of the plurality of coded functions is unregistered with a query execution engine of the DBMS; and
execute the query, wherein the executing comprises causing the query execution engine to load a given coded function of the plurality of coded functions identified by the dynamic function from a library external to the DBMS and cause the query execution engine to invoke the given coded function to perform an operation related to the DBMS.
11. The apparatus of claim 10 , wherein the instructions, when executed by the processor, further cause the processor to:
retrieve arguments related to the given coded function;
convert database management system (DBMS) types of the arguments to Java types; and
use the Java types to perform the operation.
12. The apparatus of claim 10 , wherein the instructions, when executed by the processor, further cause the processor to:
access a class that includes the given coded function by a class name; and
access the given coded function by a function name from the class that includes the given coded function.
13. A non-transitory computer readable storage medium that stores machine readable instructions that, when executed by a processor, cause the processor to:
ascertain a query for a database management system (DBMS), wherein the query comprises a dynamic function corresponding to a plurality of coded functions, each coded function of the plurality of coded functions comprises a DBMS unwrapped coded function, and each coded function of the plurality of coded functions is unregistered with a query execution engine of the DBMS; and
execute the query, wherein the executing comprises causing the query execution engine to load a given coded function of the plurality of coded functions identified by the dynamic function from a library external to the DBMS and invoke the given coded function to perform an operation related to the DBMS.
14. The non-transitory computer readable storage medium of claim 13 , wherein the given coded function is generated without using any system calls of the DBMS.
15. The non-transitory computer readable storage medium of claim 13 , wherein the instructions, when executed by the processor, further cause the processor to access a library name specified by the query.