During Hive 2 benchmark, we find Hive metastore operation take a lot of time and thus slow down Hive compilation. In some extreme case, it takes much longer than the actual query run time. Especially, we find the latency of cloud db is very high and 90% of total query runtime is waiting for metastore SQL database operations. Based on this observation, the metastore operation performance will be greatly enhanced if we have a memory structure which cache the database query result.
- is related to
HIVE-18039 Use ConcurrentHashMap for CachedStore
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