03.03.2022 20:19, Alex Peshkoff via Firebird-devel wrote:
I think there are two possible ways:
- Timeout of cached statement (counting from its first appearance in
cache, not last usage)
Yes, re-preparing all statements once per relatively big timeout should
not cause visible performance problem.
Better it should be "re-optimizing" (just CMP_post_rse) rather than
"re-preparing". The problem is that the optimizer uses the same request
pool and all its allocations are "delete-by-pool", so re-optimization is
gonna to become a memory leak. Perhaps we'll need to add an explicit
request's child pool for optimization purposes which can be re-created
during re-optimization.
- When engine detects a condition which could change a plan, it may ask
cache for invalidation.
At the first glance that's changing index active/inactive and in the
future bulk insert. That's first things that come to my mind.
It's more complex than that, but I think this is a 2nd priority task and
somewhat later I'll jump in to help with the optimizer part.
Dmitry
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