The interval with which to poll the JobTracker to the counters the jogging position. The smaller it is the a lot more load there will be about the jobtracker, the upper it's the fewer granular the caught is going to be.
The period we acquire to complete your homework will count on several elements. As an illustration, the size of the assignment or the amount of phrases will influence our expert's time to handle it.
Utmost number of objects (tables/partitions) can be retrieved from metastore in a single batch. The higher the number, the much less the volume of round trips is required to the Hive metastore server, but it really could also bring about larger memory requirement at the shopper side.
Regardless of whether to rewrite depend distinct into 2 phases, i.e., the 1st phase makes use of multiple reducers Using the count distinct essential and the 2nd phase works by using only one reducer with no key.
When enabled, this feature lets a person script to exit successfully with out consuming all the data in the normal input.
This selection indicates how much memory the nearby undertaking may take to hold The main element/benefit into an in-memory hash table when this map be a part of is accompanied by a gaggle by.
How many compactor worker threads to run on this metastore instance. Established this to a good selection on a number of scenarios of the Thrift metastore provider as Section of turning on Hive transactions. For a whole list of parameters necessary for turning on transactions, see hive.txn.manager.
By default, the cache that ORC input structure makes use of to shop the ORC file footer uses challenging references for the cached object. Placing this to true can help keep away from out-of-memory problems underneath memory strain (occasionally) at the cost of slight unpredictability in Total query performance.
The maximum information size with the dimension table that generates partition pruning details. If reaches this limit, the optimization will probably be turned off.
In stringent manner, the user need to specify at the least 1 static partition just in case the consumer try here accidentally overwrites all partitions. In nonstrict method all partitions are allowed to be dynamic.
Placing this flag to accurate will deal with legacy timestamps as time zone agnostic. Setting it to Wrong will deal with legacy timestamps as UTC-normalized.
Utmost range of reducers that should be used. In the event the a single specified in the configuration property mapred.reduce.responsibilities is detrimental, Hive will use this as the most variety of reducers when instantly determining the number of reducers.
No matter whether Hive allows the optimization about converting frequent be a part of into mapjoin depending on the click input file size. If this parameter is on, and also the sum of size for n-one with the tables/partitions for an n-way be part of is more compact than the size specified by hive.
To turn on Hive transactions, alter the values of such parameters from their defaults, as described beneath: