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23 lines
1.2 KiB
ReStructuredText
23 lines
1.2 KiB
ReStructuredText
mcsv1_udaf Introduction
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=======================
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mcsv1_udaf is a C++ API for writing User Defined Aggregate Functions (UDAF) and User Defined Analytic Functions (UDAnF) for the MariaDB Columstore engine.
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In Columnstore 1.2, functions written using this API must be compiled into the udfsdk and udf_mysql libraries of the Columnstore code branch.
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The API has a number of features. The general theme is, there is a class that represents the function, there is a context under which the function operates, and there is a data store for intermediate values.
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The steps required to create a function are:
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* Decide on a :ref:`memory allocation <memory_allocation>` scheme.
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* Create a :ref:`header file <header_file>` for your function.
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* Create a :ref:`source file <source_file>` for your function.
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* Implement :ref:`mariadb udaf api <mariadb_udaf>` code.
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* Add the function to :ref:`UDAFMap <udafmap>` in mcsv1_udaf.cpp
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* Add the function to :ref:`CMakeLists.txt <cmakelists>` in ./utils/udfsdk
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* :ref:`Compile udfsdk <compile>`.
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* :ref:`Copy the compiled libraries <copylibs>` to the working directories.
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In 1.2, Columnstore does not have a plugin framework, so the functions have to be compiled into the libraries that Columnstore already loads.
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