Nicholas Chammas nchammas

nchammas / default_language.sql

Created August 30, 2011 17:48

Recursive T-SQL CTE to find root of arbitrarily deep hierarchy

	-- schema
	--DROP TABLE dbo.common_Text;
	--DROP TABLE dbo.common_LanguageType;
	--DROP TABLE dbo.common_Comment;

	CREATE TABLE dbo.common_Comment (
	CommentId BIGINT NOT NULL PRIMARY KEY
	);

	CREATE TABLE dbo.common_LanguageType (

nchammas / simple_bank.sql

Created September 9, 2011 22:27

Simple bank schema in T-SQL

	-- required SET options for indexed view
	SET ANSI_NULLS ON;
	SET ANSI_PADDING ON;
	SET ANSI_WARNINGS ON;
	SET CONCAT_NULL_YIELDS_NULL ON;
	SET NUMERIC_ROUNDABORT OFF;
	SET QUOTED_IDENTIFIER ON;
	SET ARITHABORT ON;

	--

nchammas / checksum_collisions.sql

Created September 30, 2011 18:33

SQL Server CHECKSUM() Collisions

	-- The gist of it:
	-- Use HASHBYTES('SHA1', @input); instead of CHECKSUM(@input); if you are interested
	-- in using hashes to detect code changes.

	-- oops! I deleted too many records
	DECLARE @old_proc_definition VARCHAR(MAX) = '
	DELETE FROM dbo.transactions
	WHERE txn_id < 10000000000000000;
	';

nchammas / identity overflow check.sql

Created October 13, 2011 21:13

SQL Server IDENTITY overflow check

	-- Author: Nicholas Chammas
	-- Turbine / WB Games
	-- 2011/10/13
	-- Inspired by: http://vyaskn.tripod.com/sql_server_check_identity_columns.htm
	-- Purpose: Find all IDENTITY columns on all databases on this instance
	-- and show how much of their range they have exhausted.
	--
	-- CAVEATS
	--
	-- 1. Developed using SQL Server 2008 syntax.

nchammas / TRUNCATE and DROP are both minimally logged.sql

Created November 8, 2011 21:32

Demonstration that TRUNCATE and DROP are logged and just as fast as one another.

	SET NOCOUNT ON;
	USE [tempdb];

	CREATE TABLE a_farting_farthing (
	an_integer INT DEFAULT (1)
	);

	INSERT INTO a_farting_farthing
	DEFAULT VALUES;

nchammas / child_parent_update_locking_demo.sql

Created March 23, 2012 15:52

Updating child row does not lock parent row in SQL Server

	-- Tested on SQL Server 2008 R2
	-- Isolation level is READ COMMITTED

	--
	-- Session 1
	--
	CREATE TABLE dbo.parent (
	parent_id INT NOT NULL PRIMARY KEY
	, value VARCHAR(50) NOT NULL
	);

nchammas / foldable date functions.sql

Created May 29, 2012 05:24

Date functions like GETDATE() and SYSUTCDATETIME() are folded by the optimizer.

	SET NOCOUNT ON;
	USE [tempdb];
	GO

	-- Try substituting GETDATE() for SYSUTCDATETIME() everywhere in this script
	-- and you will get the same results.

	CREATE TABLE a_table (
	an_integer INT DEFAULT (1)
	, a_string CHAR(10) DEFAULT ('ohmigodwut')

nchammas / timer.sh

Last active August 29, 2015 14:08 — forked from esoupy/Timer.sh

A simple timer / stopwatch implemented as a bash function.

	#!/bin/bash

	# Display the duration between timer start and stop.
	#
	# Usage: timer {start\|stop} [format]
	#
	# Example:
	#
	# timer start
	# <script_commands>

nchammas / centos-spark-setup.sh

Created January 21, 2015 03:05

CentOS-based Spark development image

	yum install -y java-1.7.0-openjdk-devel gcc gcc-c++ ant git
	yum install -y wget tar unzip time

	yum install -y python-devel

	curl https://bitbucket.org/pypa/setuptools/raw/bootstrap/ez_setup.py \| python -
	curl https://raw.github.com/pypa/pip/master/contrib/get-pip.py \| python -

	easy_install pip

nchammas / February 2015 Spark Meetup Notes.md

Created February 24, 2015 05:06

Nick Chammas

Boston Spark February 2015 Meetup

This is Event #3 for this Meetup.
450+ members; Meetup started in May 2014.
New talk format: Lightning Talks
- 30 seconds to 5 minutes maximum.
- Any topic relating to Spark.
- Any skill or experience level--beginners welcome!
Speakers: We want you!