PersistenceLocation["type"]
represents a persistence location of the given type.
PersistenceLocation["type",base]
includes the base address for a location type that allows multiple locations.
PersistenceLocation
PersistenceLocation["type"]
represents a persistence location of the given type.
PersistenceLocation["type",base]
includes the base address for a location type that allows multiple locations.
Details
- Supported location types include:
-
"KernelSession" current invocation of the Wolfram Language kernel "FrontEndSession" current invocation of the Wolfram Notebook front end "Notebook" the notebook in which the current evaluation is being done "Local" local to a computer, based on user home directory "LocalShared" local to a computer, based on $BaseDirectory "Cloud" in the cloud defined by the current $CloudBase "Installation" installation defaults - PersistenceLocation["type","base"] can also be given as PersistenceLocation["type""base"].
- In functions such as PersistentSymbol that use persistence locations, the forms "type" and "type"->"base" can be used and are equivalent to PersistenceLocation["type"] and PersistenceLocation["type","base"].
- In PersistenceLocation["type"], the default base is determined by type as follows:
-
"Local" LocalObject["Persistence",$DefaultLocalBase] "LocalShared" LocalObject["Persistence",$BaseDirectory] "Cloud" CloudObject["/Persistence"] - DeleteObject[PersistenceLocation["type"]] deletes all objects stored in the given persistence location.
Examples
open all close allBasic Examples (3)
The "Local" persistence location stores values as local objects under $LocalBase:
PersistenceLocation["Local"]The "FrontEndSession" persistence location stores values in the running Wolfram Notebook front end:
PersistenceLocation["FrontEndSession"]The "Cloud" persistence location stores values as cloud objects:
PersistenceLocation["Cloud"]Scope (7)
The "KernelSession" persistence location maintains values in the kernel:
PersistenceLocation["KernelSession"]The "FrontEndSession" persistence location stores values in the running Wolfram Notebook front end:
PersistenceLocation["FrontEndSession"]The "Local" persistence location stores values as local objects under $LocalBase:
PersistenceLocation["Local"]The "LocalShared" persistence location stores values as local objects under $BaseDirectory:
PersistenceLocation["LocalShared"]The "Installation" persistence location provides default values:
PersistenceLocation["Installation"]The "Cloud" persistence location stores values as cloud objects:
PersistenceLocation["Cloud"]The "Notebook" persistence location stores values inside a kernel's evaluation notebook:
PersistenceLocation["Notebook"]Generalizations & Extensions (4)
Specify an alternate "KernelSession" location by giving a symbol name as the second argument:
mykernel = PersistenceLocation["KernelSession" -> "altvar"]Specify an alternate local location by giving the base directory as the second argument:
mylocal = PersistenceLocation["Local", FileNameJoin[{CreateDirectory[], "Test"}]]The alternate base can be given with a local object:
PersistenceLocation["Local", LocalObject["Persistence", $DefaultLocalBase]]Specify an alternate cloud location by specifying a cloud directory as the second argument:
mycloud = PersistenceLocation["Cloud", CloudObject["altLocation"]]Site administrators with write permission in $BaseDirectory can add values to the "LocalShared" location:
sharedpath = PersistenceLocation["LocalShared"][[2]]writeloc = PersistenceLocation["Local", sharedpath]Add a value to the writable variant of the shared local location:
PersistentSymbol["sitevar", writeloc] = 42;All users can now see this value:
PersistentSymbol["sitevar", "LocalShared"]Properties & Relations (4)
Persistent symbols stored at "KernelSession" are lost when the kernel is restarted:
PersistentSymbol["z", "KernelSession"] = 1;PersistentSymbol["z", "KernelSession"]Quit[];PersistentSymbol["z", "KernelSession"]Persistent symbols stored at "FrontEndSession" survive a kernel restart, as long as the front end is running:
PersistentSymbol["z", "FrontEndSession"] = 1;PersistentSymbol["z", "FrontEndSession"]Quit[];PersistentSymbol["z", "FrontEndSession"]The current default location for storing persistent symbols is a persistence location:
$PersistenceBaseThe current search path for obtaining persistent symbols is a list of persistence locations:
$PersistencePathFind all objects stored in a persistence location:
PersistentObjects[All, "KernelSession"]DeleteObject[PersistentObjects[All, "KernelSession"]]Alternatively, use DeleteObject on the persistence location:
DeleteObject[PersistenceLocation["KernelSession"]]Possible Issues (3)
The default $PersistencePath does not include the cloud location:
$PersistencePathAdding the cloud location to the search path may introduce network delays for persistent object access:
$PersistencePath = {"KernelSession", "FrontEndSession", "Local", "Cloud"}The "LocalShared" persistence location is normally read-only:
PersistentSymbol["t", "LocalShared"] = 42The "Installation" persistence location allows adding new values but not removing any values:
PersistentSymbol["t", "Installation"] = 42Remove[PersistentSymbol["t", "Installation"]]Related Guides
Text
Wolfram Research (2017), PersistenceLocation, Wolfram Language function, https://reference.wolfram.com/language/ref/PersistenceLocation.html (updated 2019).
CMS
Wolfram Language. 2017. "PersistenceLocation." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2019. https://reference.wolfram.com/language/ref/PersistenceLocation.html.
APA
Wolfram Language. (2017). PersistenceLocation. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/PersistenceLocation.html
BibTeX
@misc{reference.wolfram_2026_persistencelocation, author="Wolfram Research", title="{PersistenceLocation}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/PersistenceLocation.html}", note=[Accessed: 12-June-2026]}
BibLaTeX
@online{reference.wolfram_2026_persistencelocation, organization={Wolfram Research}, title={PersistenceLocation}, year={2019}, url={https://reference.wolfram.com/language/ref/PersistenceLocation.html}, note=[Accessed: 12-June-2026]}