1. Trio A System for Data, Uncertainty, and Lineage
Data Model
Uncertainty
Lineage
ULDBs
Uncertainty-Lineage Databases
Saw (witness,car)
(Mary,Honda) ∥ (Mary,Toyota) ∥ (Mary,Mazda)
(Susan,Lexus) ID
Drives (person,car) 21
(Bob,Honda) ∥ (Hank,Honda) 22
(Jim,Toyota) ∥ (Jim,Acura) ID
Saw (witness,car) 11
(Mary,Honda) ∥ (Mary,Toyota)
Understandable (we think )
and complete
= can represent any set of possible instances ?
Suspects = πperson(Saw ⋈ Drives)
Alternatives
Maybe annotations
Confidences ID
Suspects (person) 31
Bob ∥ Hank 32
Jim
λ(31,1) = (11,1),(21,1); λ(31,2) = (11,1),(21,2)
λ(32,1) = (11,2),(22,1) ? ?
Drives (person,car)
(Bob,Honda): 0.6 ∥ (Hank,Honda): 0.4
(Jim,Toyota): 0.2 ∥ (Jim,Acura): 0.5
See ULDB talk
Friday 11:00 AM, room 310
Lineage...
Enables simple & consistent representation of uncertain data
Correlates uncertainty in query results with uncertainty in the input data
Can make computation over uncertain data more efficient ?
Formal semantics based on possible instances
Query Language
TriQL
The Trio Query Language
Confidences in Query Results
Start with SQL …
Modify semantics for ULDBs
Default probabilistic interpretation
Saw (witness,car)
(Mary,Honda): 0.6 ∥ (Mary,Toyota): 0.4
Drives (person,car)
(Bob,Honda): 0.3 ∥ (Hank,Honda): 0.7
Relational query Q on ULDB D
semantics (logical)
implementation
Create Table Suspects(person) as
Select Drives.person
From Saw, Drives
Where Saw.car = Drives.car
Suspects (person)
Bob: 0.18 ∥ Hank: 0.42 ?
creates Suspects table with lineage to Saw and Drives
But query can override
implementation of Q D
D + Result
Select Drives.person, min(conf(Saw),conf(Drives)) as conf
From Saw, Drives …
… add constructs for querying
uncertainty and lineage
possible
instances
representation
of instances
Q on each
instance
Suspects (person)
Bob: 0.3 ∥ Hank: 0.6 ?
D1, D2, …, Dn
Q(D1), Q(D2), …, Q(Dn)
Built-in functions conf(), lineage(), lineage*()
Confidences computed on-demand
based on lineage
feature
System
System Structure
Demo Database
DDL commands
TriQL queries
Schema browsing
Table browsing
Explore lineage
On-demand
confidence
computation
TrioExplorer
(GUI client)
Command-line client
Trio API and translator
(Python)
Standard SQL
Standard relational DBMS
Encoded
Data Tables
Trio
Metadata
Lineage
Tables
Trio Stored
Procedures
DATA
UNCERTAINTY
LINEAGE