Skip to content

Instantly share code, notes, and snippets.

View Hubbitus's full-sized avatar

Pavel Alexeev aka Pahan-Hubbitus Hubbitus

  • GID.ru
  • Saint-Petersburg, Russia
View GitHub Profile
@zed
zed / time33.py
Last active April 15, 2019 09:04
time.process_time() and time.perf_counter() for Python 2 on Ubuntu.
"""time.process_time() and time.perf_counter() for Python 2 on Ubuntu."""
import ctypes
import errno
from ctypes.util import find_library
from functools import partial
CLOCK_PROCESS_CPUTIME_ID = 2 # time.h
CLOCK_MONOTONIC_RAW = 4
clockid_t = ctypes.c_int
@wolph
wolph / to_json.sql
Created April 6, 2012 10:35
Some functions to convert arrays/hstore to json :)
CREATE OR REPLACE FUNCTION escape_json (text) RETURNS text AS $$
SELECT replace($1, '''', '\'''); $$ LANGUAGE SQL IMMUTABLE;
CREATE OR REPLACE FUNCTION to_json(text) RETURNS text AS $$
SELECT escape_json($1) $$ LANGUAGE SQL IMMUTABLE;
CREATE OR REPLACE FUNCTION to_json(KEY text, value text) RETURNS text AS $$
SELECT '''' || to_json($1) || ''': ''' || to_json($2) || ''''; $$ LANGUAGE SQL IMMUTABLE;
@ohneda
ohneda / StandardDeviationCategory.groovy
Created July 21, 2011 23:07
StandardDeviation Category for groovy, inspired by Advanced Rails
import static java.lang.Math.*
import static java.math.RoundingMode.CEILING
class StandardDeviationCategory {
static Double mean(Collection list) {
list.with{
scale(sum() / size())
}
}
@hgmnz
hgmnz / query_planner.markdown
Created March 23, 2011 14:14
PostgreSQL query plan and SQL performance notes

Types of index scans

Indexes

Sequential Scan:

  • Read every row in the table
  • No reading of index. Reading from indexes is also expensive.