Hash subscription queries before acquiring tx lock #2712
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jsdt
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May 7, 2025
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This will save a lot of work for queries that already have subscribers, but it looks like we could avoid double-parsing for new queries with a little refactoring.
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gefjon
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May 9, 2025
Co-authored-by: Phoebe Goldman <phoebe@clockworklabs.io> Signed-off-by: joshua-spacetime <josh@clockworklabs.io>
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Description of Changes
Before this change we would hash subscription queries after acquiring the tx lock.
Hashing requires that we parse first so that we can determine if the query is parameterized with
:sender. However our parsersqlparseris quite slow, resulting inSubscribebeing 3x slower thanUnsubscribeaccording to some benchmarks.This patch doesn't change the parser at all. It just moves it so that it doesn't block other transactions.This patch now generates query hashes without parsing. It does so by generating two hashes and seeing if either is currently tracked by the subscription manager. Hashes are generated outside of the tx lock.
API and ABI breaking changes
None
Expected complexity level and risk
1
Testing