All indexes are done by user-defined functions, even b-trees. People can
make their own b-tree indexes by defining an operator class. Note that
"user-defined" is this case means anything called via the fmgr
interface.
Again, i think i have one more wrong understanding. My understanding is,
We are discussing about user-defined functions because, they might be actually be mutable functions, but the user might have classified as immutable. This might cause some problems while replaying the log. In the case of hash-indexes, if the hash-function is mutable, then the user has a corrupted index.
Is there some other problem also, because of user-defined functions, that will stall recovery in the proposed idea?
In our standard b-tree(with no user-defined operator classes), there shouldn't be any problem with replaying right?
Again shouldn't we say b-tree with user-defined op-classes as gist-btree? If not what is the difference between both?
Again thanks for the explanation.
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Thanks,
Gokul.