Locating data in a dataset within memory dump

Recently a troubleshooting experience led me to the need to view content of dataset in a memory dump from production server. Although, I was able to find few posts on datatable dissection, but I was curious on doing dissection from dataset to actual data. So here are the steps that I followed:

1. Locate type and eventually dataset of interest. In order to locate instance of specific type, I found dumpheap -type very useful. Place it in a loop to dump information for each instance of type found.

   • . foreach ( x {!dso -type <SomeType> -short}) { !do ${x} }

2. Next dump object (do) details for the following:
   • DataSet
   • tableCollection
   • _list
3. The _list will give an object array of name _items. Dump array (da) _items. Based pn the number of tables in dataset, you should see the addresses filled in the array. Assuming that we want to navigate to the first datatable
4. Drill further on this path via dump object/array
   • first item of _items array (first datatable)
   • columnCollection (interesting ! I always thought of navigating via rows)
   • _list (an ArrayList)
   • _items (Object array – use da).
5. At this point you see the columns. Choose a column address to view data and then continue do/da exercise.
   • dump object on any item address of the array (each is a data column)
   • Optionally, verify columnName by dumping _columnName (a string)
6. Data is stored in DataStorage type (field  _storage)
   • dump _storage (DataStorage)
   • dump _values (object array). At this point, you will have array of addresses for values of the chosen column.
7. The last step is to view data. One way is to use this command:

!da -details -nofields <address of _values>

Drop a line with your comments, suggestions or improvements.

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