Remove CacheInvalidateRelcacheByTuple and put CronJobCacheValid in shmem #295
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There is no need to call `CacheInvalidateRelcacheByTuple` when only updating the content of cron.job table( `CacheInvalidateRelcacheByTuple` should be called when the schema of crom.job udpated). Each time the `CacheInvalidateRelcacheByTuple` is called, the `Relaion` of pg_cron in launcher will be rebuilt which can lead some overhead. Instead, put `CronJobCacheValid` into shmem, and set it to false in function InvalidateJobCache.
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| CachedCronJobRelationId = InvalidOid; | ||
| } | ||
| if (!pg_atomic_unlocked_test_flag_impl(CronJobCacheValid)) | ||
| pg_atomic_clear_flag_impl(CronJobCacheValid); |
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I couldn't quite follow this approach. Shared memory does not follow transaction boundaries (we will see the valid flag become false before commit), whereas invalidations do.
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I couldn't quite follow this approach. Shared memory does not follow transaction boundaries (we will see the valid flag become false before commit), whereas invalidations do.
Yes, I have dived into the invalidation method, when the transaction commited, the pg_cron laucher can receive the invalidation messages and call 'InvalidateJobCacheCallback' to set the 'CronJobCacheValid' to be false. And when the transaction is aborted, pg_cron launcher cannot receive any messages.
I agree that using the flag in shared memory can not follow transaction boundaries, although I can use a map to store the 'transactionID' and the ' CronJobCacheValid' value for each transaction and do something in at then end of the transaction, it looks a little complex.
There is no need to call
CacheInvalidateRelcacheByTuplewhen only updating the content of cron.job table(CacheInvalidateRelcacheByTupleshould be called when the schema of crom.job udpated). Each time theCacheInvalidateRelcacheByTupleis called, theRelaionof pg_cron in launcher will be rebuilt which can lead some overhead.Instead, put
CronJobCacheValidinto shmem, and set it to false in function InvalidateJobCache.