I have seen some conflicting posts across the web about whether or not Hive uses HCatalog to access the metastore and I was hoping someone could help me out here?
Does Hive use the actual HCatalog api's to access the metastore, or does it have its own mechanism of retrieving metadata and is HCatalog only used by non-hive tools to access the metadata?
No ,hive doesn't uses Hcatalog Api to access metastore.
HCatalog opens up the hive metadata to other mapreduce tools. Every mapreduce tools has its own notion about HDFS data (example Pig sees the HDFS data as set of files, Hive sees it as tables). With having table based abstraction, HCatalog supported mapreduce tools do not need to care about where the data is stored, in which format and storage location (HBase or HDFS).