Properly close PG query stream on error #1935
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Without calling `close()`, the `queryStream` will continue to execute a query meaning there was no way to halt a long running query due to an unrecoverable downstream error. I ran into this issue while streaming IDs from a very large table as part of an ETL process. An error would occur downstream in the transformation or loading step and I needed to cancel the long-running extract stream, but there was no way to do so and I'd eventually run out of connections in the pool. This commit also handles the case when the non-callback version of stream API was used and an exception was thrown. The issue was that the promise was not reachable and therefore there was no way to add a rejection handler. This resulted in an unavoidable `Unhandled Promise Rejection` error.
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Awesome, thanks Casey! Will look to get this out soon |
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👍 you da man. I love this lib 😉 |
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Without calling
close(), thequeryStreamwill continue to execute aquery meaning there was no way to halt a long running query due to an
unrecoverable downstream error. I ran into this issue while streaming
IDs from a very large table as part of an ETL process. An error would
occur downstream in the transformation or loading step and I needed to
cancel the long-running extract stream, but there was no way to do so
and I'd eventually run out of connections in the pool.
This commit also handles the case when the non-callback version of
stream API was used and an exception was thrown. The issue was that the
promise was not reachable and therefore there was no way to add a
rejection handler. This resulted in an unavoidable
Unhandled Promise Rejectionerror.