3 ms·
As an example of something that can go wrong: Apache Impala uses LLVM to JIT queries. Turns out some code optimization algorithms are O(n^3) (or worse) or so, w
by barrkel 9y ago
As an example of something that can go wrong: Apache Impala uses LLVM to JIT queries. Turns out some code optimization algorithms are O(n^3) (or worse) or so, where n is small enough not to matter too much with human code, but falls apart with a few thousand columns in a single table, not super unusual with analytics in an environment with expensive joins like Hadoop.