I have a huge DB that I want to scale down, to only look at my area of interest. Initially I wanted to write the records I'm interested in onto a new database and table. However, this is taking for ever, so I'm wondering if it might be faster to delete the records I do not want. I already got a copy of the database, so there would be no problem to delete.
INSERT INTO NewTable (C1, C2, C3, C4, C5, C6, C7) SELECT OldTable1.C1, OldTable1.C2, OldTable1.C3, OldTable1.C4, OldTable1.C5, OldTable1.C6, OldTable1.C7 FROM OldTable1 INNER JOIN OldTable2.C5 ON OldTable2.C5 = OldTable1.C5 WHERE OldTable2.C8 = 70
If I would delete I would delete all data from OldTable1 that did not match the inner join and where statement.