neo4j/neo4j — pull request #3029 by thobe (2014-09-10 19:01:57+00:00)
Title: [2.1] Don't use exceptions for control flow

Instead of throwing exception from `indexesGetForLabelAndPropertyKey()`, return `null`. This will perform better since null checks are almost free, while throwing exceptions (especially building stack traces) are quite costly.

The problem of signalling index not present through an exception became apparent after we started building up indexed state for indexed label/property combinations in the transaction state.