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fix typos

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fjy 2014-06-04 10:14:39 -07:00
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docs/content/Performance-FAQ.md
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@ -7,7 +7,7 @@ The size of the JVM heap really depends on the type of Druid node you are runnin
[Broker nodes](Broker.html) uses the JVM heap mainly to merge results from historicals and real-times. Brokers also use off-heap memory and processing threads for groupBy queries.
[Historical nodes](Historical.html) use off-heap memory to store intermediate results, and by default, all segments are memory mapped before they can be queried. The more off-heap memory is available, the more segments can be served without the possibility of data being paged onto disk. On historicals, the JVM heap is used for [GroupBy queries](GroupByQuery.html), some data structures used for intermediate computation, and general processing. One way to calculate how much space there is for segments is: memory_for_segments = total_memory - heap - direct_memory - jvm_overhead.
[Historical nodes](Historical.html) use off-heap memory to store intermediate results, and by default, all segments are memory mapped before they can be queried. Typically, the more memory is available on a historical node, the more segments can be served without the possibility of data being paged on to disk. On historicals, the JVM heap is used for [GroupBy queries](GroupByQuery.html), some data structures used for intermediate computation, and general processing. One way to calculate how much space there is for segments is: memory_for_segments = total_memory - heap - direct_memory - jvm_overhead.
[Coordinator nodes](Coordinator nodes) do not require off-heap memory and the heap is used for loading information about all segments to determine what segments need to be loaded, dropped, moved, or replicated.