Skip to content

Instantly share code, notes, and snippets.


Jens Lechtenbörger lechten

View GitHub Profile
lechten / gist:97f07fac4adc9b7b6bca593cc0da2eef
Last active Nov 15, 2019
Query processing example for slides with the The Complete Book
View gist:97f07fac4adc9b7b6bca593cc0da2eef
-- Data from query optimization slides by Hector Garcia-Moline at
-- To be used with RelaX:
group: query evaluation plan example
description[[More or less random data.]]
R = { A, B, C
a 1 10
b 1 20
lechten / relax-example
Last active Nov 11, 2020
A gist to be used with relax for queries in the relational algebra,
View relax-example
-- To be used with RelaX:
group: bank example
description[[ Sample data for crash course on the Relational Model.
* Relation _Customer_ contains identifiers and names of customers of a bank.
* Relation _Account_ contains identifiers, customer IDs, types and balances of bank accounts. Note that a customer can have any number of accounts, while each account is owned by exactly one customer.
* Relation _BadAccount_ contains information about accounts and customers in one place.
* Query _SampleQuery_ return names of customers with high balances.