Are Datacom DB Dataset size and DB2 Dataset size the same or may be different?
For example, a dataset of an area with one table in Datacom is 5000 Tracks, when the content of that table is moved from Datacom to DB2, does 5000 tracks is sufficient or in DB2 more tracks are needed?
Release : 15.1
Unfortunately, there is no answer to your question from Datacom side.
However, IBM has surely some utility, similar to DBUTLTY Data Area Space Estimation Report, that, based on the number of rows of a table and the row length, can provide you a space estimation on DB2.
The number of rows and the row length for a table can be easily found on a CXX report or running a query on DIR_TABLE Dynamic System Table, something like:
SELECT TABLE_NAME, RECORDS, RECORD_LENGTH