[PATCH v2 0/4] box: introduce hint option for memtx tree index
Kirill Shcherbatov
kshcherbatov at tarantool.org
Wed Feb 13 12:32:24 MSK 2019
Reworked memtx tree to use 'tuple hints'.
Introduced special functions for retrieve tuple hints for a particular key_def.
Hint is an integer that can be used for tuple comparison optimization:
if a hint of one tuple is less than a hint of another then the first
tuple is definitely less than the second; only if hints are equal
tuple_compare must be called for getting comparison result.
Hints are only useful when:
* they are precalculated and stored along with the tuple;
calculation is not cheap (cheaper than tuple_compare btw) but
precalculated hints allow to compare tuples without even fetching
tuple data.
* first part of key_def is 'string', 'unsigned' or 'integer'
* since hint is calculated using only the first part of key_def
(and only first several characters if it is a string) this part
must be different with high probability for every tuple pair.
Enabled hint option improve performance on average by 15%; Select operations
are significantly accelerated (there are scenarios in which the difference
reaches 200-250%).
Changes in version 2:
-- Splitted patch to parts in other way to decrease diff
-- Hints are not index option anymore, but default where possible
-- Removed hints for numeric types
http://github.com/tarantool/tarantool/tree/kshch/gh-3961-tuple-hints
https://github.com/tarantool/tarantool/issues/3961
Alexandr Lyapunov (1):
box: introduce tuple compare hint for string index
Kirill Shcherbatov (3):
box: move memtx_tree implementation to source file
box: rework memtx_tree to store arbitrary nodes
box: rename memtx_tree.c to memtx_tree_impl.h
src/box/CMakeLists.txt | 2 +-
src/box/key_def.c | 1 +
src/box/key_def.h | 44 ++
src/box/memtx_tree.h | 68 +--
src/box/memtx_tree_decl.c | 207 +++++++++
src/box/{memtx_tree.c => memtx_tree_impl.h} | 490 +++++++++++++++-----
src/box/tuple_compare.cc | 101 ++++
src/box/tuple_compare.h | 7 +
src/coll.c | 45 ++
src/coll.h | 4 +
10 files changed, 787 insertions(+), 182 deletions(-)
create mode 100644 src/box/memtx_tree_decl.c
rename src/box/{memtx_tree.c => memtx_tree_impl.h} (55%)
--
2.20.1
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