gregrahn’s gists

gregrahn / indexes.sql

Created June 19, 2014 19:05

Zodiac example from http://structureddata.org/2007/10/31/oracle-11g-extended-statistics

	create unique index person_pk on person(person_id);
	create index person_n1 on person(date_id);
	create unique index calendar_pk on calendar(date_id) ;

gregrahn / tpcd_ri_mysql.log

Created May 21, 2014 05:56

	--------------
	alter table call_center add constraint cc_d1 foreign key (cc_closed_date_sk) references date_dim (d_date_sk)
	--------------

	Query OK, 6 rows affected (0.03 sec)
	Records: 6 Duplicates: 0 Warnings: 0

	--------------
	alter table call_center add constraint cc_d2 foreign key (cc_open_date_sk) references date_dim (d_date_sk)
	--------------

gregrahn / presto-vs-impala.txt

Last active April 6, 2018 22:23

	Three comparison points:
	Presto + RCFile vs Impala + RCFile vs Impala + Parquet

	Note: Query time, CPU utilization, Disk read tput (KBRead)

	Impala v1.1.1
	Presto v0.52
	================================================================================================================================
	Presto + RCFile:
	select ss_sold_date_sk, count(*) from store_sales_rcfile group by 1 order by 1 limit 2000;

gregrahn / graphdb-simulator.cpp

Created October 9, 2013 06:24 — forked from apurvam/graphdb-simulator.cpp

	/* Instructions on compilation and execution
	* =========================================
	*
	* Compile this program with pthreads:
	*
	* g++ -Wall -lpthread -o graphdb-simulator graphdb-simulator.cpp
	*
	* Before you run this program, you need to create the following
	* directories:
	*

gregrahn / tweet2csv.py

Created August 15, 2013 05:20

translate tweet json to a CSV file

	#!/usr/bin/env python
	# encoding: utf-8

	import sys
	import urllib
	import codecs
	import json
	import unicodecsv
	import dateutil.parser as parser

gregrahn / bart-2012-salaries.tsv

Last active December 19, 2015 06:59

2012 Bart Salaries. Extracted from Public Employee Salaries Database. http://www.mercurynews.com/salaries/bay-area?Entity=Bay%20Area%20Rapid%20Transit

We can make this file beautiful and searchable if this error is corrected: It looks like row 2 should actually have 11 columns, instead of 12 in line 1.

	Entity Name Title Base Overtime Other (vacation, sick, bonus, etc) Medical/Dental/Visual Employeer Contribution to Pension Employee Contribution to Pension Paid By Employer Employer Contribution to Deferred Compensation (401k) Misc Total Cost of Employment
	Bay Area Rapid Transit Dugger, Dorothy General Mgr 298700 0 34500 14951 39521 23324 1869 6796 419661
	Bay Area Rapid Transit Crunican, Grace General Mgr 312461 0 3846 19141 37513 17500 1869 7591 399921
	Bay Area Rapid Transit Tietz, Forrest Police Sergeant 136746 111902 33921 18200 60630 156 0 1107 362662
	Bay Area Rapid Transit Pangilinan, Edgardo Asst Controller 107785 0 214322 10903 13017 7650 1869 5734 361279
	Bay Area Rapid Transit Lucarelli, Frank Police Lieutenant 173811 46280 33422 23364 76427 233 0 5019 358556
	Bay Area Rapid Transit Collier, Roberta Asst Treasurer 33971 0 289534 1797 4072 2378 1869 4897 338518
	Bay Area Rapid Transit Parker, Thomas Exec Mgr Transit System Compl 136544 0 145633 19139 16863 9923 1869 5584 335554
	Bay Area Rapid Transit Ra

gregrahn / values.sql

Created June 20, 2013 21:20

Example of PostgreSQL VALUES() functionality in Cloudera Impala. Examples: https://issues.cloudera.org/browse/IMPALA-68 http://www.postgresql.org/docs/9.2/static/sql-values.html

	[impala1:21000] >
	select *
	from (values ('2013-06-01' as col1),
	('2013-06-02'),
	('2013-06-02'),
	('2013-06-03'),
	('2013-06-04'),
	('2013-06-05')
	) x;

gregrahn / create_tables.sql

Created December 2, 2012 06:05

Experiment to see if it is possible to rewrite the SQL query to not use a join and compute the count(distinct) in a single pass of the data.

	drop table t2;
	create table t2
	(
	day_id int not null,
	time_id date not null,
	begin_time date not null,
	end_time date not null
	);

	begin

gregrahn / gist:3877498

Created October 12, 2012 05:34

ethtool eth0

	$ sudo ethtool eth0
	Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes: 10baseT/Half 10baseT/Full
	100baseT/Half 100baseT/Full
	1000baseT/Full
	Supports auto-negotiation: Yes
	Advertised link modes: 10baseT/Half 10baseT/Full
	100baseT/Half 100baseT/Full
	1000baseT/Full

gregrahn / demo_rdbms.mk

Created August 20, 2012 21:46

demo_rdbms.mk from Oracle 11.2

	#
	# Example for building demo OCI programs:
	#
	# 1. All OCI demos (including extdemo2, extdemo4 and extdemo5):
	#
	# make -f demo_rdbms.mk demos
	#
	# 2. A single OCI demo:
	#
	# make -f demo_rdbms.mk build EXE=demo OBJS="demo.o ..."

Greg Rahn gregrahn