Azat Khuzhin 2996b38606 Add ability to configure maximum load factor for the HASHED/SPARSE_HASHED layout ... As it turns out, HashMap/PackedHashMap works great even with max load factor of 0.99. By "great" I mean it least it works faster then google sparsehash, and not to mention it's friendliness to the memory allocator (it has zero fragmentation since it works with a continuious memory region, in comparison to the sparsehash that doing lots of realloc, which jemalloc does not like, due to it's slabs). Here is a table of different setups: settings | load (sec) | read (sec) | read (million rows/s) | bytes_allocated | RSS - | - | - | - | - | - HASHED upstream | - | - | - | - | 35GiB SPARSE_HASHED upstream | - | - | - | - | 26GiB - | - | - | - | - | - sparse_hash_map glibc hashbench | - | - | - | - | 17.5GiB sparse_hash_map packed allocator | 101.878 | 231.48 | 4.32 | - | 17.7GiB PackedHashMap 0.5 | 15.514 | 42.35 | 23.61 | 20GiB | 22GiB hashed 0.95 | 34.903 | 115.615 | 8.65 | 16GiB | 18.7GiB **PackedHashMap 0.95** | **93.6** | **19.883** | **10.68** | **10GiB** | **12.8GiB** PackedHashMap 0.99 | 26.113 | 83.6 | 11.96 | 10GiB | 12.3GiB As it shows, PackedHashMap with 0.95 max_load_factor, eats 2.6x less memory then SPARSE_HASHED in upstream, and it also 2x faster for read! v2: fix grower Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>		2023-05-19 06:07:21 +02:00
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_snippet_dictionary_in_cloud.md	New nav - reverting the revert	2023-03-17 21:45:43 -05:00
index.md	Add ability to configure maximum load factor for the HASHED/SPARSE_HASHED layout	2023-05-19 06:07:21 +02:00