Fix possible NPE
Merge remote-tracking branch 'origin/develop' into develop
Issue #2276. OChainedIndexProxy: Improve non composite index usage.
Issue #2276. OChainedIndexProxy: Allow to use non composite hash index.
Issue #2276. SQL Select. Search for indexes. remove code duplication.
Minor: refactoring
Minor: refactoring
Issue #2276. SQL Select. Refactoring of: Index existence
Issue #2276. SQL Select. Search for indexes. remove code duplication.
Minor: refactoring
Issue #2276. OChainedIndexProxy: Improve non composite index usage.
Issue #2276. OChainedIndexProxy: Improve non composite index usage.
Merge branch 'develop' into orientdb-2276
Merge remote-tracking branch 'origin/develop' into develop