Auto-close result returned from getResultSet - #781
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`ResultSet` objects returned from `Statement#executeQuery()` is closed automatically, when its parent statement is closed. Per JDBC specification: > When a Statement object is closed, its current ResultSet object, if > one exists, is also closed. Though, when a `ResultSet` is obtained from `Statement#execute()` + `Statement.getResultSet()`, such `ResultSet` was not considered to be a "current ResultSet object" because, according to the spec: > This method [`Statement.getResultSet()`] should be called only once per > result. Thus such result set was not closed automatically. Such code is used in practice and it has started to cause a memory leak (of the full materialized result set) after duckdb#533 was added. This PR fixes the leak by retaining the `ResultSet`, returned from `Statement.getResultSet()`, as a "current ResultSet object" and closing it automatically on `Statement` close. Testing: new tests added to `TestClosure` Fixes: duckdb#780
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This is a backport of the PR #781 to `v1.5-variegata` stable branch. `ResultSet` objects returned from `Statement#executeQuery()` is closed automatically, when its parent statement is closed. Per JDBC specification: > When a Statement object is closed, its current ResultSet object, if > one exists, is also closed. Though, when a `ResultSet` is obtained from `Statement#execute()` + `Statement.getResultSet()`, such `ResultSet` was not considered to be a "current ResultSet object" because, according to the spec: > This method [`Statement.getResultSet()`] should be called only once per > result. Thus such result set was not closed automatically. Such code is used in practice and it has started to cause a memory leak (of the full materialized result set) after #533 was added. This PR fixes the leak by retaining the `ResultSet`, returned from `Statement.getResultSet()`, as a "current ResultSet object" and closing it automatically on `Statement` close. Testing: new tests added to `TestClosure` Fixes: #780
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ResultSetobjects returned fromStatement#executeQuery()is closed automatically, when its parent statement is closed.Per JDBC specification:
Though, when a
ResultSetis obtained fromStatement#execute()+Statement.getResultSet(), suchResultSetwas not considered to be a "current ResultSet object" because, according to the spec:Thus such result set was not closed automatically.
Such code is used in practice and it has started to cause a memory leak (of the full materialized result set) after #533 was added.
This PR fixes the leak by retaining the
ResultSet, returned fromStatement.getResultSet(), as a "current ResultSet object" and closing it automatically onStatementclose.Testing: new tests added to
TestClosureFixes: #780