Each utility has a corresponding (C++) function that is wrapped by a Minirel transaction (necessary for recovery). The utilities that are currently supported are described below.


To insert a tuple into a relation, the relation name must be passed, and the number and values of attributes must be passed. The values are type checked (with the needed Catalog calls taking place). The tuple is created, then inserted into the HeapFile and any indexes that exist.


All tuples that match a given selection will be deleted from a relation. For example:

from Relation R
where name = "bob"

Everyone named bob will be deleted. Multiple attributes cannot be checked. Indexes are updated as needed.


It is often convenient to enter many tuples at a time. The load utility allows this. Only a relation name and a filename are needed. Indexes are updated as needed.

Click here for the interface.

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