SQL Training - 04

• after 255 hit at the same time it will be put in the queue
• Data loss in simple backup is very high
• Unique key may allow null
• De-normalization: using joining 
• Don't delete cascade
• Cluster Indexing: Like Phone book (restructuring pages)
• Non Clustered Indexing: Like Book Index (فهرس الكتاب)(no restructuring for the pages just create index for the newly pages or edited pages)

--select [name], recovery_model_desc from sys.databases;

--alter database one set recovery simple;

--backup log one to disk = N'c:\tmp\one.trn';

--backup database one to disk = N'c:\temp\one.bak';

--alter database one set recovery full;

backup log one to disk = N'c:\temp\one.trn'; --you cannot make backup for log file before creating full backup

backup database one to disk  = N'c:\temp\one.bak';

Case Study: Fleet Management Systems

• Main Entities
• Car (Detailed Data on each vehicle)
• Make(This is a description of all vehicle)
• Shape(This contains the possible shapes)
• Vendor(These are approved vendors which can be used to supply parts)
• Maintenance (his data contains description of all the maintenance operations performed  )
• Parts(This table represents parts that have been take out of inventory)