Database System Principles

Database System Principles - CS245:DatabaseSystem Principles

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CS 245 Notes 1 1 CS 245: Database System  Principles Notes 01: Introduction Hector Garcia-Molina
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CS 245 Notes 1 2 Isn’t Implementing a Database  System Simple? Relations Statements Results
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CS 245 Notes 1 3 Introducing the Database Management System  The latest from Megatron Labs  Incorporates latest relational technology  UNIX compatible
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CS 245 Notes 1 4 Megatron 3000  Implementation Details First sign non-disclosure agreement
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CS 245 Notes 1 5 Megatron 3000  Implementation Details Relations stored in files (ASCII) e.g., relation R is in /usr/db/R Smith # 123 # CS Jones # 522 # EE . . .
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CS 245 Notes 1 6 Megatron 3000  Implementation Details Directory file (ASCII) in /usr/db/directory R1 # A # INT # B # STR … R2 # C # STR # A # INT … . . .
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CS 245 Notes 1 7 Megatron 3000 Sample Sessions % MEGATRON3000 Welcome to MEGATRON 3000! % . . .
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CS 245 Notes 1 8 Megatron 3000 Sample Sessions from R # Relation R A B C SMITH 123 CS &
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CS 245 Notes 1 9 Megatron 3000 Sample Sessions from R,S where R.A = S.A and S.C > 100 # A B 123 CAR 522 CAT &
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CS 245 Notes 1 10 Megatron 3000 Sample Sessions from R | LPR # Result sent to LPR (printer).
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CS 245 Notes 1 11 Megatron 3000 Sample Sessions from R where R.A < 100 | T # New relation T created.
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CS 245 Notes 1 12 Megatron 3000 To execute “ select * from R where condition ”: (1) Read dictionary to get R attributes (2) Read R file, for each line: (a) Check condition (b) If OK, display
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CS 245 Notes 1 13 Megatron 3000 To execute “ select * from R where condition | T ”: (1) Process select as before (2) Write results to new file T (3) Append new line to dictionary
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CS 245 Notes 1 14 Megatron 3000 To execute “ select A,B from R,S where condition ”: (1) Read dictionary to get R,S attributes (2) Read R file, for each line: (a) Read S file, for each line: (i) Create join tuple (ii) Check condition (iii) Display if OK
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CS 245 Notes 1 15 What’s wrong with the  Megatron 3000 DBMS?
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CS 245 Notes 1 16 What’s wrong with the  Megatron 3000 DBMS? Tuple layout on disk
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This note was uploaded on 02/21/2011 for the course CS 245 taught by Professor Dr.hector during the Winter '02 term at SUNY Buffalo.

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Database System Principles - CS245:DatabaseSystem Principles

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