4.2.6. Hard Drive Cache / Gel Files

let’s assume that you are developing a very large transformation graph containing dozens of actions one of these actions requires extra care because its parameters needs extra tuning you are forced to run several time this “difficult” action before obtaining the correct values of its parameters let’s assume that this “difficult to tune” action occurs at the “end” of the transformation graph i e each time you want to test a new set of parameters for this “difficult” action, you are forced to wait for a very long time because there are many, many other actions to run before executing the “difficult” action with the new parameters to test in this somewhat common situation, it would be nice to “save on the hard drive” a backup of all the input tables of this “difficult” action in this way, the next time that you run the “difficult” action (with another set of parameters to test), you can directly use the backed up tables, instead of re running the whole transformation graph from the start this “hard drive backup” is commonly named a “hd (hard drive) cache” or “anatella gel file” an “anatella gel file” contains a complete “snapshot” of one table, frozen in time ( hence the name “gel file” – gel means “freeze” in french) the “gel files” are extremely useful when developing new large and difficult transformations because it allows you to test very rapidly (nearly in real time), many different parameters of your “difficult to tune” actions thanks to the unique automatic “hd cache” feature of anatella, developing new complex transformation graphs is a “child play”! the development time of large transformation graph is usually divided by 10, compared to other etl inside the anatella graph window, you can visually check which output pins have a corresponding “hd cache”/”gel file” these are the output pins with an orange border for example this (orange) output pin possesses an “anatella gel file” this (green) output pin possesses an “anatella gel file” and the content of this file is visible inside the data preview window this (red) output pin does not accept any “anatella gel file” (any “hd cache” files will be deleted as soon as the graph starts this happens when using the advanced multi threading execution techniques see section 5 3 2 4) when you are in “run mode” (i e when the button in the main toolbar is “checked”), you can create, for (nearly) any output pin, a new “gel file” simply click on the required output pin click on any orange pin and instantaneously see the corresponding data table in the data preview window the preview is based on the available “gel file” and appears instantaneously (it does not require any computation at all)