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Chapter 3 Concise History of SQL

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Chapter 3 Concise History of SQL Powered By Docstoc
					  IFS180.81 Intro. to Data 
       Management



Chapter 3
Concise History of SQL
History of DBMS
n Hierarchical Database Structure
n Where structure is formed by data groups, 
  subgroups, and further subgroups
n Strength – capturing and storing transactional 
  data
n Major weakness – difficult for ad-hoc or on-
  demand queries 
History of DBMS
    DEPT # Dept Name     Reports To   Manager   Budget



              Emp # Emp Name Dept # Sex Salary Grade


  Job# Job Description


                    Job Date Title      Child Name Age Sex



                     Salary Date   Salary


   System / Program had to navigate forward / backward
   thru branches
History of DBMS
n Network Database Structure
n Developed to allow retrieval of specific 
  records
n Utilizes a system of ‘Pointers’ (RRN’s)
n No longer had to follow branches
n Major weakness – maintenance of Pointers
History of DBMS
    Extremely Fast for Querying Data, Slow for TPS


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History of DBMS
n Relational DBMS – 1970 Codd & Date
n Based Upon relational algebra and Set 
  Theory from 1800’s.
n Sets of object are considered as a whole
n Relational algebra (simplest form) are truth 
  tables. And / Or / Nor 
n Fast ad-hoc queries and TP 
History of SQL
n English like Query Language was developed 
  to manipulate data in RDBMS (structured 
  query language)
n Relational Software (aka Oracle)
n Cal Berkley (INGRES)
n IBM (DB/2)
        History of SQL
        n American National Standards Institute (ANSI) SQL 
           Standard:
 Year   Name         Alias                                                       Comments



1986    SQL-86   SQL-87      First published by ANSI. Ratified by ISO in 1987.

                             Lacked Referential Integrity 
1989    SQL-89               Minor revision.



1992    SQL-92   SQL2        Major revision.
                             Focusing on Standardization


1999    SQL:19   SQL3        Added regular expression matching, recursive queries, triggers, non-scalar types and some object-oriented 
        99                   features. (The last two are somewhat controversial and not yet widely supported.)




2003    SQL:20               Introduced XML-related features, window functions, standardized sequences and columns with auto-
        03                   generated values (including identity-columns). 
                             (See Eisenberg et al.: SQL:2003 Has Been Published.)
History of SQL
n Even though SQL is a standard, all major 
  vendors have their version
n Oracle = PL/SQL
n IBM = SQL PL
n Microsoft = Transact SQL
History of SQL
n Why so many versions of SQL 
  Implementations?
n Size / Complexity of ANSI Standard
n Missing components from STD (Indexing)
n Ambiguity of standard
n Backwards compatibility 
n Need to be careful and know what vendor you 
  are working with

				
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posted:7/13/2013
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