| Author: | Tom Hebbron |
|---|---|
| Version: | 1.0 (first public release) |
| Date: | 2013-11-05 |
This small extension module provides a few useful functions and casts for working with bit strings (i.e., bit varying) in PostgreSQL. They scratch a small but specific itch - perhaps they will be useful.
You will need the PostgreSQL development environment installed:
apt-get install postgresql-server-dev
Then, to build and install, do:
make sudo make install psql -d <database> -c "CREATE EXTENSION bitstring_helpers"
OK, great, here's what you get.
shuffled_ints(bigint) RETURNS bigint[]
Create an array of user definable size n of shuffled integers (1 to n)
popcount(bit varying) RETURNS int
Count the number of 1s in a bitstring
hamming_distance(bit varying, bit varying) RETURNS int
Calculate the hamming distance between two bit varying bitstrings (must both be the same length).
neighbours(bit varying) RETURNS SETOF bit varying
Return all the 1-bit mutation neighbours of the given bitstring.
text2bitstring(text) RETURNS bit varying
Convert text (contianing 1's and 0's only) to a bit varying type.
bit2text(bit varying) RETURNS text
Convert bit varying to text
Concatenates elements from arrays of any type into a single array.
Two aggregates for bits and for text - both concatenate elements into one long string (text) or bit varying (bits).
That's all folks.