GC asks cohorts if statement is okay. Cohort says yes / no

IF YES - commit, release data locks, complete transaction ; IF NO - rollback, release locks, undo transaction

GC send canCommit? to cohort, if NO abort

GC sends preCommit to cohort, GC enters prepared state, Cohort replies with ACK message

GC sends do commit to cohort, all members commit, cohort sends have committed back

more connections to the database

more connections to the database

less network traffic for users, less processing for clients, simpler security management

set of terms with well defined meanings

classification for a vocabulary e.g sex{male, female}

specification of a conceptualisation e.g "sex must only be one of" {male, female} - constraints and assumptions

effort, time, inflexible, situational

XML, RDF, remote relational databases

unstructured data format

1 large central table - fact table, set of smaller tables arranged around fact table - dimension tables