Author: rambocoder

Database persistence via Entity Models

Access to the models goes into src/adapters or src/repository. A Repository mediates between the domain and data mapping layers, acting like an in-memory domain object collection (POEAA).

Business logic, coordination and controlling transactions goes into src/services

Mappers between Input Model and Entity Models go into src/transformers

Routing of requests goes to src/controllers and repository is injected into the controllers

Naming test: Noun_Should_Verb

AAA Testing Pattern

Do not have more than one assert per test, or if you do, test the same concept.

Do not test database in unit tests, it slows down your tests and it is not reproducible: complicates set up and tear down

Pass fake repository/adapter into controller or business logic class

• Arrange
• Act
• Assert

Builder pattern

Constructor initializer

class Point {
    constructor(private x:number, private y: number){}
}

Union types

const x: number | string = 60;

Attributes (AOP)

See a list of all the indexes in the database

select * from sys.dm_db_index_physical_stats(null,null,null,null,null)

Index fragmentation

SELECT DB_NAME() AS DatabaseName,
Object_name(i.object_id) AS TableName,
i.index_id,
name AS IndexName,
avg_fragmentation_in_percent
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL, NULL, 'Limited') AS ips
INNER JOIN sys.indexes AS i ON ips.object_id = i.object_id AND ips.index_id = i.index_id
ORDER BY avg_fragmentation_in_percent desc

Show filegroups and db files

select * from sys.filegroups
select * from sys.database_files

Additional commands

SET SHOWPLAN_XML OFF
GO
SET STATISTICS PROFILE OFF
SET STATISTICS IO ON
-- clear query plans
dbcc freeproccache;
-- clear buffer cache
dbcc dropcleanbuffers;

Examples using AdventureWorks2016

use AdventureWorks2016

select pp.name
from Production.Product pp
join Sales.SalesOrderDetail ss
on pp.ProductID = ss.ProductID
join Sales.SalesOrderHeader oh
on ss.SalesOrderID = oh.SalesOrderID;

select check_clause from INFORMATION_SCHEMA.CHECK_CONSTRAINTS
where CONSTRAINT_NAME = 'CK_Employee_SickLeaveHours';

SET STATISTICS PROFILE on

SELECT  sql_text.text, last_execution_time, creation_time
FROM    sys.dm_exec_query_stats AS stats
        CROSS APPLY sys.dm_exec_sql_text(stats.sql_handle) AS sql_text
order by last_execution_time DESC

SELECT * FROM sys.dm_exec_query_transformation_stats

EXEC sys.sp_updatestats @resample = '' -- char(8)

SET TRANSACTION ISOLATION LEVEL REPEATABLE READ
BEGIN TRANSACTION

	SELECT TOP 100 * FROM AdventureWorks2016CTP3.Person.Person-- WITH(TABLOCKX);

	SELECT resource_type, request_mode, COUNT(*) AS lock_count
	FROM sys.dm_tran_locks
	WHERE request_session_id = @@SPID
	GROUP BY resource_type, request_mode;

ROLLBACK

DBCC SHOW_STATISTICS ('Person.Person', 'IX_Person_LastName_FirstName_MiddleName')

SELECT * FROM sys.stats
WHERE OBJECT_ID = OBJECT_ID('Person.Person')
ORDER BY stats_id;

DBCC SHOW_STATISTICS ('Person.Person', 'PK_Person_BusinessEntityID')

DBCC SHOW_STATISTICS ('Person.Person', 'IX_Person_LastName_FirstName_MiddleName')

SELECT * FROM Person.Person WHERE LastName = 'Alonso';

SELECT * FROM Person.Person WHERE LastName = 'Acca';

See the query plans

SELECT 		databases.name,
	dm_exec_sql_text.text AS TSQL_Text,
	dm_exec_query_stats.creation_time, 
	dm_exec_query_stats.execution_count,
	dm_exec_query_stats.total_worker_time AS total_cpu_time,
	dm_exec_query_stats.total_elapsed_time, 
	dm_exec_query_stats.total_logical_reads, 
	dm_exec_query_stats.total_physical_reads, 
	dm_exec_query_plan.query_plan
FROM sys.dm_exec_query_stats 
CROSS APPLY sys.dm_exec_sql_text(dm_exec_query_stats.plan_handle)
CROSS APPLY sys.dm_exec_query_plan(dm_exec_query_stats.plan_handle)
INNER JOIN sys.databases
ON dm_exec_sql_text.dbid = databases.database_id
WHERE dm_exec_sql_text.text LIKE '%t_item_master%';

• BravoDelta : Early GitHub and what appears to be the latest version
• Cucumberl Presentation : GitHub
• Kucumberl : GitHub

• http://stackoverflow.com/questions/5837776/how-to-load-thrift-client-in-erlang
• http://kungfooguru.wordpress.com/2009/08/31/erlang-thrift-and-hbase/

sudo apt-get install libboost-dev
tar -zxvf thrift*.tar.gz
cd thrift*
./configure
make
cd compiler/cpp
./thrift -gen erl Hbase.thrift

{ok, TFactory} = thrift_socket_transport:new_transport_factory("localhost", 9090, []).
{ok, PFactory} = thrift_binary_protocol:new_protocol_factory(TFactory, []).
{ok, Protocol} = PFactory().
{ok, C0} = thrift_client:new(Protocol, hbase_thrift).

{ok, C0} = thrift_client_util:new("localhost", 9090, hbase_thrift, []).

% Load records into the shell
rr(hbase_types).

% Get a list of tables
{C1, Tables} = thrift_client:call(C0, getTableNames, []).

% Create a table
{C2, _Result} = thrift_client:call(C1, createTable, ["test", [#columnDescriptor{name="test_col:"}]]).

% Insert a column value
% TODO: Investigate the attributes dictionary's purpose
{C3, _Result} = thrift_client:call(C2, mutateRow, ["test", "key1", [#mutation{isDelete=false,column="test_col:", value="wooo"}], dict:new()]).

% Delete
{C4, _Result} = thrift_client:call(C3, mutateRow, ["test", "key1", [#mutation{isDelete=true}], dict:new()]).

% Get data
% TODO: Investigate the attributes dictionary's purpose
thrift_client:call(C4, getRow, ["test", "key1", dict:new()]).

     hasher.initialized.add(crossroads.parse, crossroads);
     hasher.changed.add(crossroads.parse, crossroads);
     hasher.init();

     crossroads.addRoute("select/{item}", function (item) {
           viewModel.selectedItem(item);
     });

crossroads.addRoute("select/{item}", function (item) {
  viewModel.selectedItem(item);
});
function handleChanges(newHash, oldHash) {
  crossroads.parse(newHash);
};
hasher.changed.add(handleChanges);
hasher.initialized.add(handleChanges);
hasher.init();

wget http://www.erlang.org/download/otp_src_R15B.tar.gz
tar xfvz otp_src_R15B.tar.gz

sudo apt-get install build-essential git-core libwxgtk2.8-dev libgl1-mesa-dev libglu1-mesa-dev libpng3 wx-common default-jre default-jdk fop

sudo apt-get build-dep erlang

./configure
make
make docs
sudo make install
sudo make install-docs