Improve ResourceOwners' behavior for large numbers of owned objects.
The original coding was quite fast so long as objects were always
released in reverse order of addition; otherwise, it degenerated into
O(N^2) behavior due to searching for the array element to delete.
Improve matters by switching to hashed storage when the number of
objects of a given type exceeds 64. (The cutover point is open to
discussion, of course, but some simple performance testing suggests
that hashing has enough overhead to be a loser below there.)
Also, refactor resowner.c so that we don't need N copies of the array
management code. Since all the resource IDs the code currently needs
to deal with are either pointers or integers, it seems sufficient to
create a one-size-fits-all infrastructure in which everything is
converted to a Datum for storage.
Aleksander Alekseev, reviewed by Stas Kelvich, further fixes by me
Branch
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master
Details
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http://git.postgresql.org/pg/commitdiff/cc988fbb0bf60a83b628b5615e6bade5ae9ae6f4
Modified Files
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src/backend/access/hash/hashfunc.c | 3 +
src/backend/utils/resowner/resowner.c | 955 +++++++++++++++------------------
2 files changed, 446 insertions(+), 512 deletions(-)
