An action is any operation you do on a table or worksheet that changes its state, such as performing a tabulation, selecting rows, or creating a computed column. A query is a set of one or more actions that are combined to achieve a particular result.
In 1010data, you can edit actions you've already taken, add new actions, undo the last action, or undo all the actions you've taken on a particular table or worksheet. You can also go back one or more steps in your analysis, and then subsequently go forward once again through those same steps as you develop a query.
1010data gives you a number of ways to edit your actions. You can either use the drag-and-drop interface of the GUI to add to, delete from, modify, or rearrange your current set of actions. Or, you can directly edit the Macro Language XML that comprises the current query. For example, suppose you created a computed column, performed a tabulation, then sorted the result. You might want to go back and change the formula of the computed column (perhaps because you made a mistake or because you would like to try another formula). Rather than repeat all the steps, you could edit the actions to change the computed column and then rerun the query.
There are certain practices that can make your queries more efficient, such as performing selections that eliminate the greatest number of rows first or using G_Functions on segmented tables instead of tabulations. You can find a list of suggestions on these topics as well as a range of others including sorting, linking, merging, and writing selection expressions in Writing Efficient Queries.
You can save the actions associated with a particular table or worksheet by downloading the Macro Language XML as a text file on your computer. Or, you can save the current set of actions as a Quick Query, which allows you to parameterize inputs so that you can change certain query values each time you run it. In addition, you may download the Macro Language XML for all of your saved Quick Queries (or a subset of them) as a text file to your computer.