Drizzle/bzr dependency

A number of developers had problems on Friday at the Drizzle Developer Day with compiling bzr . The distro in question I was helping with was CentOS 5 32-bit. I had no issues on CentOS 5 64bit.

Today while creating the first deployed Drizzle AWS AMI I discovered the same problem using Ubuntu 8.10 Intrepid 32 bit.

The solution was actually rather trivial. Installing the python-dev package solved the problem.

apt-get install python-dev

Bzr 1.13.1 Compiling error

building 'bzrlib._btree_serializer_c' extension
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.5 -c bzrlib/_btree_serializer_c.c -o build/temp.linux-i686-2.5/bzrlib/_btree_serializer_c.o
bzrlib/_btree_serializer_c.c:4:20: error: Python.h: No such file or directory
bzrlib/_btree_serializer_c.c:5:26: error: structmember.h: No such file or directory
bzrlib/_btree_serializer_c.c:35: error: expected specifier-qualifier-list before ‘PyObject’
....
bzrlib/_btree_serializer_c.c:1651: error: request for member ‘f_lineno’ in something not a structure or union
bzrlib/_btree_serializer_c.c:1651: warning: statement with no effect
bzrlib/_btree_serializer_c.c:1652: warning: implicit declaration of function ‘PyTraceBack_Here’

  Cannot build extension "bzrlib._btree_serializer_c".
  Use "build_ext --allow-python-fallback" to use slower python implementations instead.

error: command 'gcc' failed with exit status 1
Tagged with: Compiling Databases Drizzle General Open Source

Producing Alternative Means statistics with SQL

Producing Alternative Means statistics with SQL

MySQL’s built-in AVG() computes the arithmetic mean — the sum divided by the count. That is the right default for many questions, but it is not always the right measure of central tendency.

Extending MySQL Capabilities with UDFs, Plugins and Components

Extending MySQL Capabilities with UDFs, Plugins and Components

MySQL offers three different approaches to extending the SQL capabilities with the default product you download and install. These are: User Defined Function (UDF) MySQL Manual MySQL Plugin MySQL Manual MySQL Component MySQL Manual For the purposes of this post I will be using the current LTS version MySQL 8.

Producing One-Sample Z-Test statistics with SQL

Producing One-Sample Z-Test statistics with SQL

The one-sample Z-test determines whether a sample mean differs significantly from a known population mean when the population standard deviation is also known. It is the appropriate test when the population parameters are established — quality control benchmarks, national averages, long-run process measurements — and you want to evaluate whether a new sample is consistent with them.