There's currently no way of knowing the determinicity of an UDF.
And the optimizer and the sequence() UDFs were making wrong
assumptions about what the is_const member means.
Plus there was no implementation of update_system_tables()
causing the optimizer to overwrite the information returned by
the <udf>_init function.
Fixed by equating the assumptions about the semantics of
is_const and providing a implementation of update_used_tables().
Added a TODO item for the UDF API change needed to make a better
implementation.
Previously, UDF *_init functions were passed constant strings with erroneous lengths.
The length came from the containing variable's size, not the length of the value itself.
Now the *_init functions get the constant as a null terminated string with the correct
length supplied too.
Previously, UDF *_init functions were passed constant strings with erroneous lengths.
The length came from the containing variable's size, not the length of the value itself.
Now the *_init functions get the constant as a null terminated string with the correct
length supplied.
problem #1: udf_example.so does not get built on AIX
solution#1: build it yourself using
cd sql; gcc -g -I ../include/ -I /usr/include/ -lpthread \
-shared -o udf_example.so udf_example.c; mv udf_example.so \
.libs/
problem#2 (the bug): udf_example fails because it does not
recognize the variable LD_LIBRARY_PATH when doing dl_open(),
it looks at LIBPATH
solution#2: add the library path to LIBPATH
problem#3: udf_example returns the wrong result length since
it relies on strmov to return a pointer to the end of the
string that it copies. On AIX builds, where m_string.h is not
included (m_string defines a macro expanding strmov to stpcpy),
there is a macro expanding strmov to strcpy, which returns a
pointer to the first character.
solution#3: define strmov as stpcpy.
problem#4: #2 applies on hp-ux as well, but this platform
looks at SHLIB_PATH
solution#4: added the library path to SHLIB_PATH
The code that set up data to be passed to user-defined functions was very
old and analyzed the "Type" of the data that was passed into the UDF, when
it really should analyze the "return_type", which is hard-coded for simple
Items and works correctly for complex ones like functions.
---
Added test at Sergei's behest.
