Web Search Overview Crawling IR Documents vs. Database Records Database records (or tuples in relational databases) are typically made up of well-defined fields (or attributes) e.g., bank records with account numbers, balances, names, addresses, social security numbers, dates of birth,etc. Easy to compare fields with well-defined semantics to queries in order to find matches Text is more difficult 6Web Search Overview & Crawling 6 Documents vs. Database Records ▪ Database records (or tuples in relational databases) are typically made up of well-defined fields (or attributes) ▪ e.g., bank records with account numbers, balances, names, addresses, social security numbers, dates of birth, etc. ▪ Easy to compare fields with well-defined semantics to queries in order to find matches ▪ Text is more difficult IR