Is there are simple way to copy SQL table to local root file as TTree?
I tried to use methods TTreeSQL->CopyTree or ->CloneTree and got an Error in TClass::New :
cannot create object of class TTreeSQL.
Many thanks, IGor.
Should CloneTree and CopyTree work for TTreeSQL?
I tried to copy and analyse SQL table of size 40X4e6 by using a function
The data retrieving is extremely slow, therefore this way is not useful.
Will be appreciated if any one can share experience to copy and analyse a large SQL tables.
When I changed an event reading order from last->0 to 0->last the reading speed increased significantly.
But reading speed is still relatively slow 100000 rows per 3 min.
The reading of the SQL table is relatively (especially compare to a ROOT file …)