More memory-efficient internal representation for Strings: call for more data

Vitaly Davidovich vitalyd at
Tue Dec 2 22:13:21 UTC 2014

Any consideration towards removing the char[] (or byte[]) indirection
altogether? .NET for example stores the bytes inline with the instance.

Sent from my phone
On Dec 2, 2014 4:59 PM, "Aleksey Shipilev" <aleksey.shipilev at>

> Hi,
> As you may already know, we are looking into more memory efficient
> representation for Strings:
> As part of preliminary performance work for this JEP, we have to collect
> the empirical data on usual characteristics of Strings and char[]-s
> normal applications have, as well as figure out the early estimates for
> the improvements based on that data. What we have so far is written up
> here:
> We would appreciate if people who are interested in this JEP can provide
> the additional data on their applications. It is double-interesting to
> have the data for the applications that process String data outside
> Latin1 plane. Our current data says these cases are rather rare. Please
> read the current report draft, and try to process your own heap dumps
> using the instructions in the Appendix.
> Thanks,
> -Aleksey.

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