Highest number of entries within the vector GROUP BY aggregation hashtables. Exceeding this could induce a flush regardless of memory stress problem.
Produces essential schema with a startup if one particular does not exist. Reset this to Phony, following developing it as soon as.
Annotation of the operator tree with statistics data demands column statistics. Column statistics are fetched with the metastore.
Percentage of overall memory for use by map-aspect group aggregation hash desk, when this team by is followed by map be part of.
No matter whether to check, convert, and normalize partition value laid out in partition specification to conform into the partition column form.
The main difference between this paramater and hive.optimize.skewjoin is this parameter makes use of the skew information saved during the metastore to improve the prepare at compile time itself. If there's no skew data while in the metadata, this parameter will never have any result.
To clean up the Hive scratch directory though starting up the Hive server (or HiveServer2). It's not an selection for a multi-person surroundings since it will unintentionally remove the scratch Listing in use.
Some pick out queries is usually transformed to an individual FETCH task, minimizing latency. Currently the query needs to be single sourced not possessing any subquery and should not have any aggregations or distincts (which incur RS – ReduceSinkOperator, requiring a MapReduce undertaking), lateral sights and joins.
Optimum range of rows allowed for any scaled-down subset of information for easy Restrict, whether it is a fetch query. Insert queries are usually not restricted by this Restrict.
Adjustment to mapjoin hashtable size derived from desk and column statistics; the estimate of the number of keys is divided by this price. If the worth is 0, statistics usually are not made use of and hive.hashtable.initialCapacity is utilized in its place.
When legitimate the HDFS location stored from the index file is going to be overlooked at runtime. If the information obtained moved or even the title on the cluster received modified, the index data should continue to be usable.
The canonical list of configuration Houses is managed while in the HiveConf Java class, so check with the HiveConf.java file for a whole list of configuration Houses obtainable with your Hive release.
To operate the MSCK REPAIR Desk command batch-wise. If there is a lot of untracked partitions, by configuring a value towards the assets it will eventually execute in batches internally. The default worth of the home is zero, which means it will eventually execute the many partitions directly.
Regardless of whether to browse around this web-site help Log4j2's asynchronous logging. Asynchronous logging can give important overall performance enhancement as logging might be taken care of within a independent thread that makes use visit here of the LMAX disruptor queue for buffering log messages.