This document describes a framework for enabling Java stored procedures in MySQL. It discusses four major tasks: 1) linking MySQL to the Java Virtual Machine using JNI, 2) modifying MySQL's language syntax to support Java, 3) updating MySQL classes/tables to recognize Java procedures, and 4) building a framework to load Java classes and invoke methods at runtime. Key aspects include storing Java bytecode in MySQL tables, a custom class loader that retrieves classes from the database, and an invocation API that translates parameters and calls methods. The project adds all elements needed for Java procedures in MySQL.

1. MySQL/JVM A Framework for Enabling Java Language Stored Procedures in MySQL Kevin Tankersley

3. The available function libraries typically focus on numeric, date, time, and string functions

5. Network Access and Consuming web services

7. Microsoft SQL Server allows stored procedures to be written in .NET

8. PostgreSQL allows procedures to be written in several external languages, including Java

10. Use MySQL as the database because it is open source and widely used

11. Use Java as the language because it is multi-platform and widely known

12. Design for compliance with ISO standards

15. Link the project to the Java Virtual Machine

16. Modify the MySQL language syntax to accommodate Java routines

17. Modify classes, tables, and support libraries to recognize Java routines

19. Platform for making native calls between Java runtime and C/C++

20. Supports callbacks from Java code, or JVM invocation from C/C++

21. Requires the shared library jvm.dll and the header jni.h at compile time

23. JVM Thread Linkage Example

25. Link the project to the Java Virtual Machine

26. Modify the MySQL language syntax to accommodate Java routines

27. Modify classes, tables, and support libraries to recognize Java routines

29. MySQL uses the GNU Bison parser

30. Parser reads user query and creates a parse tree descriptor of type LEX*

31. Server libraries use the classes and data in LEX* to carry out the request

34. Link the project to the Java Virtual Machine

35. Modify the MySQL language syntax to accommodate Java routines

36. Modify classes, tables, and support libraries to recognize Java routines

39. Alter procedure definition code

40. Alter class sp_head

41. Change structure st_chistics

43. Link the project to the Java Virtual Machine

44. Modify the MySQL language syntax to accommodate Java routines

45. Modify classes, tables, and support libraries to recognize Java routines

47. A system for storing compiled Java code

48. A classloading mechanism to locate and define classes at runtime

49. A parameter translation API to convert MySQL data types to JVM data types

51. More secure: No need to give developers file system access

52. More manageable: Easier for developers and DBAs to track installed libraries

53. More portable: Paths, environment variables, file permissions vary between platforms

54. New Tables

55. Mysql.jclass: Class files

56. Mysql.jmethod: Method descriptions

58. Create a custom class loader that knows how to get classes from DB

59. Need to link custom loader to DB

60. Using JDBC is problematic

61. Solution: Use JNI Callbacks

62. Create a server function get_jclass to access mysql.jclass through native table handlers

63. Use a native method in the class loader

65. Created JParam API to manage conversions between MySQL types and JVM types

66. Numerics:

67. Need to map MySQL types to Java types of equal or greater width (e.g. TINYINT to byte)

68. Runtime checks for unsigned overflow

69. Strings:

70. MySQL: Support for many encodings

72. When Created:

73. Attaches to JVM

74. Locates bytecode for class loader

75. Defines class loader

76. When Called:

77. Parse method signature

78. Locate bytecode for entry class

79. Define entry class with class loader

80. Translate parameters to JVM types

81. Invoke method on entry class

83. Framework to link MySQL to JVM

84. Standards-compliant changes to the language

85. Modifications to existing elements of stored procedure execution

87. Role-based security model for JVM resources

88. Fully native JDBC Driver

89. New server configuration variables

90. A bytecode cache

91. User-defined types

93. References

94. Questions