i ntroduction of w eek 14 assignment discussion graded: 3-1-4 (lab4: query optimization) ...
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INTRODUCTION OF WEEK 14 Assignment Discussion
Graded: 3-1-4 (Lab4: Query Optimization) Creating, reviewing, and interpretation are all important for this assignment. Analysis of execution plans: scan (full table, index range, index unique), order
of execution, join operations (hash, nested loop) Comparing the plans, not statistics Complexity of plan != efficiency of the query: I/O scans, sorting, joins are
expensive Understanding application query tuning
Due: 12-1 (Database Storage), 12-2 (Bulk Data Movement) Working: 13-1 (Research paper: database metadata management) Working: 3-1-5 (Final Project Write-up)
Review of previous week and module Metadata Management, Database Management Tools Oracle 10g Data Dictionary and Dynamic Performance Views
Overview of this week – Module 5 Data Warehouse Administration Course Summary Final Exam Discussion
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MODULE 5 Metadata, Tools, and Data WarehousingSection 4 Data Warehouse Administration
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DATA WAREHOUSE AND CHARACTERISTICS
A data warehouse is a subject-oriented, integrated, time-variant, non-volatile collection of data that is designed for query and analysis rather than for transaction processes.
Subject-oriented – data pertains to a particular subject instead of the many subjects pertinent to the company’s ongoing operations.
Integrated – consistent naming conventions, formats, encoding structures; from multiple data sources
Time-variant – data is identified with a particular time period, can study trends and changes
Non-updatable – data is stable in a data warehouse. Data loaded, and should not be removed.
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DATA WAREHOUSE AND BUSINESS INTELLIGENCE
A data warehouse usually contains historical data derived from transaction data and other sources.
It enables an organization to consolidate data.
It includes An extraction, transportation, transformation,
and loading (ETL) solution An online analytical processing (OLAP) engine Client analysis tools Reporting
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ANALYTICAL VS. TRANSACTION PROCESSING
Analytical processing – informational systems DSS – decision support system OLAP – online analytical processing Data mining – the process of mining or discovery of new
information in terms of patterns or rules from vast amounts of data
Transaction processing – operational system OLTP – online transaction processing
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DATA WAREHOUSE DESIGN
Star schema - data modeling technique used to map multidimensional decision support data into a relational database. It is excellent for ad-hoc queries, but bad for online transaction processing. It contains four components: Fact table Dimension tables Attributes Attribute hierarchies
Snowflake schema – a star schema in which the dimension tables have additional relationships
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DATA MOVEMENT – ETL PROCESS
ETL – Extract, Transform, and Load Capture – extract or obtaining a snapshot of a chosen
subset of the source data for loading into the data warehouse
Scrub or data cleansing – uses pattern recognition and AI techniques to upgrade data quality
Transform – convert data from format of operational system to format of data warehouse
Load – place transformed data into the warehouse and create indexes
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DATA WAREHOUSE PERFORMANCE
Perspectives of data warehouse performance Extract performance – how ETL process performs Data management – database design and data quality Query performance – OLAP tuning Server performance – hardware support
Automated summary tables Provide a proper set of aggregate information Commonly implement with materialized views or batch
operation tables
DBMS features to support data warehousing Materialized views – automatically creation of summaries Bitmap indexes – widely used in data warehousing, in
addition to B-tree Parallel execution – multiple processes work together
simultaneously to run a single SQL statement
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THE RULES OF THUMB
Personal DBA handbook Write down your own experience Categorize them in a searchable note or repository
Backup everything and plan for worst all the time Before making any changes, ensure that you can
recover from them
Automation and share your knowledge Create a systematic way to troubleshoot problems Create, reuse and share scripts Knowledge sharing will open many revenues for you
Next levels Understand the business, not just the technology Keep up-to-date on technology
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COURSE SUMMARY (YOUR LEARNING)
DBA Roles and Responsibilities DBMS Architecture, Physical and Logical
Structures DBMS Installation and Database Creation Database Connectivity and Network
Components Database Security and Audit Capability Database Backup and Recovery Database Monitoring, DBMS System Tuning,
Physical Configuration Optimization SQL Query Coding and Tuning, Data
Loading Database Metadata, Data Dictionary Data Warehouse Characteristics and
Overview
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FINAL EXAM Midterm coverage (30%) Backup choices, recover mechanisms and high availability
features Performance influential factors, Database performance tuning Optimizer overview and optimizer influential factors Oracle query optimizer processing, statistics collection,
execution plan Oracle physical and logical database structures Space management, RAID technology The load utility, data pump export and import DBMS Metadata, metadata type Oracle data dictionary, dynamic performance views Data warehouse, characteristic differences vs. operational
database, analytic (OLAP) vs. transactional processing (OLTP) Data warehouse database design (star schema), ETL
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SCHEDULE REMINDER ONE MORE TIME
Final exam can be taken between Thursday, Dec. 8 and the week after Wednesday, Dec. 14.
The final exam must be completed on or before Wednesday of Week 15, not Sunday! Check with your proctor or test center.
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All assignments are due by Sunday, December 11, and no late assignments will be accepted after the date.
Please review your grade book, and let me know any missing grades right way.