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From "Jeff Jirsa"<>
Subject Re: Does select queries objects will be allocated in new_heap ??
Date Thu, 06 Jul 2017 05:19:06 GMT

On 2017-07-05 21:50 (-0700), Pranay akula <> wrote: 
> Hai,
> I have a small doubt i am not much familiar with java, so when a select or
> insert query is executed against a node does the output of that query will
> be stored in heap ??

SELECT will create a number of short-lived objects on the heap, yes, but it's not like the
memtable - there is not a read-side memtable. Most of the objects are transient and should
be collected before being promoted to old gen. There are some exceptions - the key and partition
caches are counterexamples.

> For insert query the output will stored in Memtables will is part on
> new_heap right ?? does select and other queries also use the new_heap or
> just writes ??

Just writes.

> Is there any document available correlating queries and heap objects.

Very much version dependent, there are some great videos around about the read path - Tyler's
is probably as authoritative as you'll find

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