# ISLOCALTOGLOBALMAPPINGHASH
hash implementation of the `ISLocalToGlobalMapping` object. When `ISGlobalToLocalMappingApply()` is used this is good for large memory problems. 
## Options Database Keys

- ***-islocaltoglobalmapping_type hash -*** select this method





## Note
This is selected automatically for large problems if the user does not set the type.


## See Also
 [](sec_scatter), `ISLocalToGlobalMappingCreate()`, `ISLocalToGlobalMappingSetType()`, `ISLOCALTOGLOBALMAPPINGBASIC`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/utils/isltog.c.html#ISLOCALTOGLOBALMAPPINGHASH">src/vec/is/utils/isltog.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/vec/is/utils/isltog.c)


[Index of all IS routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
