Implements technical analysis functions as MariaDB/MySQL UDFs.

Functions available:

• TA_SMA: Simple Moving Average
• TA_SSMA: Smoothed Simple Moving Average
• TA_EMA: Exponential Moving Average
• TA_RSI: Relative Strength Index
• TA_TR: True Range
• TA_SUM: Running Sum, as opposed to aggregate sum provided by MariaDB/MySQL.
• TA_STDDEVP: Running Standard Deviation, as opposed to the aggregate provided by MariaDB/MySQL.
• TA_PREVIOUS: Calculation True Range
• TA_MAX: Running Minimum
• TA_MIN: Running Maximum

Other indicators which can be derived from those functions include:

• MACD: Moving Average Convergence/Divergence
• Bollinger Bands
• ADX

Source repository: https://github.com/joaocosta/lib_mysqludf_ta

Linux requires the installation of libtool, automake and autoconf:

sudo apt-get install libtool automake autoconf

Once done, proceed with the compilation & installation:

./configure
make
sudo make install

If this fails, run ./autogen.sh and repeat the ./configure && make && make install sequence.

./autogen.sh
./configure
make && make install

A binary DLL is shipped with this release: feel free to copy it to the MariaDB/MySQL plugin directory. To find out what the MariaDB/MySQL plugin directory is, run this in a prompt:

SHOW VARIABLES LIKE 'plugin_dir';

The following article describes how to compile MySQL UDFs in Windows: http://rpbouman.blogspot.com/2007/09/creating-mysql-udfs-with-microsoft.html

For more information on compiling MySQL UDFs:

• http://dev.mysql.com/doc/refman/5.1/en/udf-compiling.html
• http://dev.mysql.com/doc/refman/5.1/en/adding-udf.html

Execute the following SQL depending on the platform:

CREATE FUNCTION ta_ema RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_max RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_min RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_previous RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_rsi RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_sma RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_ssma RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_sum RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_stddevp RETURNS REAL SONAME 'lib_mysqludf_ta.so';
CREATE FUNCTION ta_tr RETURNS REAL SONAME 'lib_mysqludf_ta.so';

CREATE FUNCTION ta_ema RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_max RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_min RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_previous RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_rsi RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_sma RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_ssma RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_stddevp RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_sum RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_tr RETURNS REAL SONAME 'lib_mysqludf_ta.dll';

This assumes a local default MySQL instance with username 'root' with no password defined

make check

To try the examples below, import the provided sampledb.sql into a MySQL database:

mysqladmin -u root create lib_ta
mysql -u root lib_ta < sampledb.sql
mysql -u root lib_ta

ta_ema(
    float data, 
    int period
)

• data - The data to average
• period - Running period to calculate for

To calculate a 50 period EMA of closing prices:

SELECT `datetime`, ta_ema(`close`, 50)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_sma(
    float data, 
    int period
)

• data - The data to average
• period - Running period to calculate for

To calculate a 50 period SMA of closing prices:

SELECT `datetime`, ta_sma(`close`, 50)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

A smoothed moving average, as used to calculate ATR and RSI. See also: https://en.wikipedia.org/wiki/Moving_average#Modified_moving_average

ta_ssma(
    float data,
    int period
)

• data - The data to average
• period - Running period to calculate for

To calculate a 50 period SMA of closing prices:

SELECT datetime, ta_ssma(ta_tr(high, low, close), 14)
FROM ( SELECT * FROM EURUSD_86400 ORDER BY datetime ASC ) AS T;

ta_rsi(
    float data, 
    int period
)

• data - The data to calculate rsi for
• period - Running period to calculate for

To calculate a 14 period RSI of closing prices:

SELECT `datetime`, ta_rsi(`close`, 14)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

To calculate a 10 period ta_ema of ta_rsi(14):

SELECT `datetime`, ta_ema(ta_rsi(`close`, 14), 10)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_stddevp(
    float data, 
    int period
)

• data - The data to calculate on
• period - Running period to calculate for

This function is useful for calculating indicators such as Bollinger Bands.

To calculate the upper limit Bollinger Band of 2 standard deviations over a 21 period sma:

SELECT `datetime`, ( ta_sma(`close`,21)   2*ta_stddevp(`close`,21) ) AS `BOL_UP`
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

To calculate the lower limit Bollinger Band of 2 standard deviations over a 21 period sma:

SELECT `datetime`, ( ta_sma(`close`,21) - 2*ta_stddevp(`close`,21) ) AS `BOL_DOWN`
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_sum(
    float data, 
    int period
)

• data - The data to average
• period - Running period to calculate for

To calculate a 50 running sum of closing prices:

SELECT `datetime`, ta_sum(`close`, 50)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_tr(
    float high,
    float low,
    float close
)

• high - The Highest price for the period
• low - The Lowest price for the period
• close - The Closing price of the period

To calculate True Range

SELECT `datetime`, ta_tr(`high`, `low`, `close`)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_previous(
    float data,
    int period
)

• data - The data to lookback into
• period - Number of periods to look back into

See if today's close is greater than yesterday's close:

SELECT `datetime`, close > ta_previous(`close`,1)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_max(
    float data,
    int period
)

• data - The data to search the maximum for
• period - Running period to calculate for

To return the maximum close over the last 50 periods:

SELECT `datetime`, ta_max(`close`, 50)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

ta_min(
    float data,
    int period
)

• data - The data to search the minimum for
• period - Running period to calculate for

To return the minimum close over the last 50 periods:

SELECT `datetime`, ta_min(close, 50)
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

MACD is defined as the difference between two EMAs:

SELECT `datetime`, ta_ema(`close`,12) - ta_ema(`close`,26) AS `MACD`
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

The MACD signal line is defined as an EMA of the MACD:

SELECT `datetime`, ta_ema(ta_ema(`close`,12) - ta_ema(`close`,26), 9) AS `MACD_SIGNAL`
FROM ( SELECT * FROM `EURUSD_86400` ORDER BY `datetime` ASC ) AS T;

Financial data tends to be stored as floats, however sometimes it might be useful to run these functions with integer data. This can be achieved by using MariaDB/MySQL's CAST():

SELECT ta_ema(CAST(integer_data_field AS DECIMAL(65), 14) FROM `price_table`;

• The easiest way would be to copy one of the existing .c files to a different name and modify its implementation.
• Edit test/03_test.sh and add a suitable test to validate results of the new function using the provided dataset.
• Add a setup script for your new function under the setup directory. These are used by automated deployment mechanisms.
• Edit Makefile.am and add the new source file.
• To generate a new configure script, run the provided autogen.sh (this depends on automake, autoconf and libtool being installed).

João Costa [email protected]