Invest Once, Save a Million Times - LLVM-based Expression Compilation in PostgreSQL

Abstract

We demonstrate how a surgical change to PostgreSQL’s evaluation strategy for SQL expressions can have a noticeable impact on overall query runtime performance. (This is an abridged version of [BG16], originally demonstrated at VLDB 2016.) The evaluation of scalar or Boolean expressions often takes the backseat in a discussion of query processing although table scans, filters, aggregates, projections