Reduce lock requirements during recompression #7747
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Recompression used to take heavy Exclusive lock on chunk while it recompressed data. This blocked a lot of concurrent operations like inserts, deletes, and updates. By reducing the locking requirement to ShareUpdateExclusive, we enable more concurrent operations on the chunk and hypertable while relying on tuple locking. Recompression can still end up taking an Exclusive lock at the end in order to change the chunk status but it does this conditionally, meaning it won't take it unless it can do it immediatelly.
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Recompression used to take heavy Exclusive lock on chunk while it recompressed data. This blocked a lot of concurrent operations like inserts, deletes, and updates. By reducing the locking requirement to ShareUpdateExclusive, we enable more concurrent operations on the chunk and hypertable while relying on tuple locking. Recompression can still end up taking an Exclusive lock at the end in order to change the chunk status but it does this conditionally, meaning it won't take it unless it can do it immediately.