diff --git a/coverage/sqldata.py b/coverage/sqldata.py
index 12676d0bb..e2ec0a3b1 100644
--- a/coverage/sqldata.py
+++ b/coverage/sqldata.py
@@ -615,24 +615,19 @@ def touch_files(self, filenames: Collection[str], plugin_name: Optional[str] = N
                     # Set the tracer for this file
                     self.add_file_tracers({filename: plugin_name})
 
-    def purge_files(self, filenames: Iterable[str], context: Optional[str] = None) -> None:
+    def purge_files(self, filenames: Iterable[str]) -> None:
         """Purge any existing coverage data for the given `filenames`.
 
-        If `context` is given, purge only data associated with that measurement context.
+        This removes all coverage data for the files, but does not remove
+        them from the list returned my measured_files(), so the file_ids
+        for the files will remain constant over time.
         """
 
         if self._debug.should("dataop"):
-            self._debug.write(f"Purging {filenames!r} for context {context}")
+            self._debug.write(f"Purging {filenames!r}")
         self._start_using()
         with self._connect() as con:
 
-            if context is not None:
-                context_id = self._context_id(context)
-                if context_id is None:
-                    raise DataError("Unknown context {context}")
-            else:
-                context_id = None
-
             if self._has_lines:
                 table = 'line_bits'
             elif self._has_arcs:
@@ -644,12 +639,8 @@ def purge_files(self, filenames: Iterable[str], context: Optional[str] = None) -
                 file_id = self._file_id(filename, add=False)
                 if file_id is None:
                     continue
-                self._file_map.pop(filename, None)
-                if context_id is None:
-                    q = f'delete from {table} where file_id={file_id}'
-                else:
-                    q = f'delete from {table} where file_id={file_id} and context_id={context_id}'
-                con.execute(q)
+                q = f'delete from {table} where file_id={file_id}'
+                con.execute_void(q)
 
     def update(self, other_data: CoverageData, aliases: Optional[PathAliases] = None) -> None:
         """Update this data with data from several other :class:`CoverageData` instances.
diff --git a/tests/test_api.py b/tests/test_api.py
index 885831550..d278d2da7 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -777,15 +777,16 @@ def test_purge_filenames(self) -> None:
         assert [1, 2] == sorted_lines(data, fn1)
         assert [1,] == sorted_lines(data, fn2)
 
-        # Purge one file's data and one should remain
+        # Purge one file's data and only the other should have data, but
+        # both are still listed as measured
         data.purge_files([fn1])
-        assert len(data.measured_files()) == 1
+        assert len(data.measured_files()) == 2
         assert [] == sorted_lines(data, fn1)
         assert [1,] == sorted_lines(data, fn2)
 
-        # Purge second file's data and none should remain
+        # Purge second file's data
         data.purge_files([fn2])
-        assert len(data.measured_files()) == 0
+        assert len(data.measured_files()) == 2
         assert [] == sorted_lines(data, fn1)
         assert [] == sorted_lines(data, fn2)
 
@@ -805,7 +806,7 @@ def test_purge_filenames_context(self) -> None:
         def dummy_function() -> None:
             unused = 42
 
-        # Start/stop since otherwise cantext
+        # Start/stop since otherwise context cannot be set
         cov = coverage.Coverage()
         cov.start()
         cov.switch_context('initialcontext')
@@ -823,38 +824,25 @@ def dummy_function() -> None:
         assert len(sorted_lines(data, __file__)) == 1
         assert len(data.measured_contexts()) == 2
 
-        # Remove specifying wrong context should raise exception and not remove anything
-        try:
-            data.purge_files([fn1], 'wrongcontext')
-        except coverage.sqldata.DataError:
-            pass
-        else:
-            assert 0, "exception expected"
+        # Remove one file; measurements are gone but files and contexts remain registered
+        data.purge_files([fn1])
         assert len(data.measured_files()) == 3
-        assert [1, 2] == sorted_lines(data, fn1)
-        assert [1,] == sorted_lines(data, fn2)
-        assert len(sorted_lines(data, __file__)) == 1
-        assert len(data.measured_contexts()) == 2
-
-        # Remove one file specifying correct context
-        data.purge_files([fn1], 'testcontext')
-        assert len(data.measured_files()) == 2
         assert [] == sorted_lines(data, fn1)
         assert [1,] == sorted_lines(data, fn2)
         assert len(sorted_lines(data, __file__)) == 1
         assert len(data.measured_contexts()) == 2
 
-        # Remove second file with other correct context
-        data.purge_files([__file__], 'initialcontext')
-        assert len(data.measured_files()) == 1
+        # Remove second file
+        data.purge_files([__file__])
+        assert len(data.measured_files()) == 3
         assert [] == sorted_lines(data, fn1)
         assert [1,] == sorted_lines(data, fn2)
         assert len(sorted_lines(data, __file__)) == 0
         assert len(data.measured_contexts()) == 2
 
-        # Remove last file specifying correct context
-        data.purge_files([fn2], 'testcontext')
-        assert len(data.measured_files()) == 0
+        # Remove last file
+        data.purge_files([fn2])
+        assert len(data.measured_files()) == 3
         assert [] == sorted_lines(data, fn1)
         assert [] == sorted_lines(data, fn2)
         assert len(sorted_lines(data, __file__)) == 0