Affects Version/s: 0.13.0
Fix Version/s: None
"hive.stats.fetch.column.stats" controls whether the column stats for a table are fetched during explain (in Tez: during query planning). On my setup (1 table 4000 partitions, 24 columns) the time spent in semantic analyze goes from ~1 second to ~66 seconds when turning the flag on. 65 seconds spent fetching column stats...
The reason is probably that the APIs force you to make separate metastore calls for each column in each partition. That's probably the first thing that has to change. The question is if in addition to that we need to cache this in the client or store the stats as a single blob in the database to further cut down on the time. However, the way it stands right now column stats seem unusable.
|Field||Original Value||New Value|
|Assignee||Sergey Shelukhin [ sershe ]|
|Status||Patch Available [ 10002 ]||Resolved [ 5 ]|
|Resolution||Fixed [ 1 ]|