Hi John, Thanks a lot for the pointer to the article!
Can I understand that what the DataStore Viewer shows as Encoded key is what the article refers to as "prefix delta encoding scheme" ? It is supposed to save space by in my cases keys (encoded and decoded) are of approx same size. didier Could you explain though the difference between encoded and decoded version of the key On Jul 20, 10:53 am, John Patterson <[email protected]> wrote: > Yes, the kind name is used in the key along with the id/name and > ancestor path and all contribute to the size. > > Details:http://code.google.com/appengine/articles/storage_breakdown.html > > On 20 Jul 2010, at 15:41, Didier Durand wrote: > > > @John Patterson, > > I did not mention the Class / Kind in my answer for the following > > reason: when I go to "Datastore Viewer" in the GAE Console and for > > every entity, I see "Decoded key" and "Encoded key" > > > The encoded key is always - at least in my experience - a huge string > > whatever the size of the decoded key (including the string for Kind) > > is. > > > So, does it really matter to have a short Kind name if the encoded > > version (probably the one used by Datastore) is huge? > > > I would be interested to know this if anyone knows. > > regards > > didier > > > On Jul 20, 8:27 am, John Patterson <[email protected]> wrote: > >> Also the class name is used in the Key as the kind. To get the > >> shortest keys you would need to use short class names and numeric > >> long > >> ids (rather than Strings). Having small keys is important because > >> they are stored many times per entity in indexes and more than once > >> for the entity itself. > > >> I know that both Twig and Objectify have support for defining your > >> own > >> kind names without needing to actually rename your class to something > >> incomprehensible. > > >> On 20 Jul 2010, at 11:11, Didier Durand wrote: > > >>> Hi Mark, > > >>> I would say yes: the datastore viewer shows the data with couples > >>> (name,value), name being the origianal attribute name in the java > >>> class. > > >>> Moreover the doc says "Each persistent field of the class > >>> represents a > >>> property of the entity, with the name of the property equal to the > >>> name of the field (with case preserved)." at > >>>http://code.google.com/appengine/docs/java/datastore/dataclasses.html > >>> ... > > >>> regards > >>> didier > > >>> On Jul 19, 3:32 pm, Mark <[email protected]> wrote: > >>>> Hi, > > >>>> I read in a post that the length of member variable names > >>>> contributes > >>>> to the amount of storage space your app uses, example: > > >>>> class Farm { > >>>> private String mFarmersFavoriteCropToPlant; > >>>> } > > >>>> would take more space to store than: > > >>>> class Farm { > >>>> private String m; > >>>> } > > >>>> might not matter for a handful of instances, but if I have > >>>> thousands > >>>> of records... is this true? > > >>>> Thanks > > >>> -- > >>> You received this message because you are subscribed to the Google > >>> Groups "Google App Engine for Java" group. > >>> To post to this group, send email to > >>> [email protected] > >>> . > >>> To unsubscribe from this group, send email to > >>> [email protected] > >>> . > >>> For more options, visit this group > >>> athttp://groups.google.com/group/google-appengine-java?hl=en > >>> . > > > -- > > You received this message because you are subscribed to the Google > > Groups "Google App Engine for Java" group. > > To post to this group, send email to [email protected] > > . > > To unsubscribe from this group, send email to > > [email protected] > > . > > For more options, visit this group > > athttp://groups.google.com/group/google-appengine-java?hl=en > > . -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
