1 xml et. al vs tables michael stonebraker adjunct professor massachusetts institute of technology...
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XML et. al vs Tables
Michael Stonebraker
Adjunct Professor
Massachusetts Institute of Technology
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M.I.T.
TablesTablesTablesTables
Good for structured dataremember Codd’s laws
Schema first have to think about your data up front
Data integrity keynot loosey-goosey semantics
Good for structured dataremember Codd’s laws
Schema first have to think about your data up front
Data integrity keynot loosey-goosey semantics
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M.I.T.
XMLXMLXMLXML
Good for documents Bad for data (Codd’s laws)Schema later okLoosey-goosey ok
Good for documents Bad for data (Codd’s laws)Schema later okLoosey-goosey ok
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M.I.T.
Applicability
structure
little lots
data
volume
little
lots
XML
Tables
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M.I.T.
Why?Why?Why?Why?
Low end content uses HTML -> XMLHigh end content uses DBMS
invariably structuredHigh end business data processing uses
DBMSLow end may well use XML
because it is easier
Low end content uses HTML -> XMLHigh end content uses DBMS
invariably structuredHigh end business data processing uses
DBMSLow end may well use XML
because it is easier
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M.I.T.
Which is More Important?Which is More Important?Which is More Important?Which is More Important?
Internet has generated lots of HTML
content (on the left)As well as lots of click stream data (on
the right)Which is more important depends on
metricbytes represented?bytes * monetary value of a byte?market value?
Internet has generated lots of HTML
content (on the left)As well as lots of click stream data (on
the right)Which is more important depends on
metricbytes represented?bytes * monetary value of a byte?market value?
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M.I.T.
Nothing is NewNothing is New Nothing is NewNothing is New
Document systems have never used data
bases IR community versus DBMS communityXML will allow better IR
Outer fringes have never used data bases in the 1970’s it was airline reservation
systems in the 1990’s it was web crawlers
Document systems have never used data
bases IR community versus DBMS communityXML will allow better IR
Outer fringes have never used data bases in the 1970’s it was airline reservation
systems in the 1990’s it was web crawlers
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M.I.T.
But DBMS is “Good”But DBMS is “Good”But DBMS is “Good”But DBMS is “Good”
Makes you think about you data up frontgood discipline (used by business
data processing folks)registers meta data for downstream
data sharabilityTransactions, recovery, etc. are good
Makes you think about you data up frontgood discipline (used by business
data processing folks)registers meta data for downstream
data sharabilityTransactions, recovery, etc. are good
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M.I.T.
Battleground Between The Two Battleground Between The Two ApproachesApproachesBattleground Between The Two Battleground Between The Two ApproachesApproaches
Corporate media asset managementScientific data
Corporate media asset managementScientific data
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M.I.T.
How Can DBMS Do Better?How Can DBMS Do Better?How Can DBMS Do Better?How Can DBMS Do Better?
Become easier to useBetter tools
Become easier to useBetter tools
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M.I.T.
My Main FearMy Main FearMy Main FearMy Main Fear
Two fiefdoms are incompatibleshades of Corba and Comcross fiefdom joins may not work well
DBMS will export XMLno guarantee that client won’t update
it and hand it backhorrible view update problem….
Two fiefdoms are incompatibleshades of Corba and Comcross fiefdom joins may not work well
DBMS will export XMLno guarantee that client won’t update
it and hand it backhorrible view update problem….