The Positional Index

• Projection-like Index with matching column removed from the table

• Can have multiple columns (e.g., no TPC-D query asks for ExtPrice or Discount alone)

CustKey

Qty

Discount

ExtPrice

CK1

Q1

D1

E1

CK2

Q2

D2

E2

CK3

Q3

D3

E3

CK4

Q4

D4

E4

Base Table

Qty

Q1

Q2

Q3

Q4

Positional Indexes

Discount

ExtPrice

D1

E1

D2

E2

D3

E3

D4

E4

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