Amos Bird
8f28a36c17
Use internal iteration over hash tables in Aggregator.
...
For compound hash tables such as the future StringHashMap, an
iterator-based API might be inefficient for iterating over a table or
for merging two tables, because:
1) the key has to be converted to a general format from a from a
component-specific format, which may differ between the components;
2) the information about the component of the compound hash table to
which the value belongs is lost, and has to be recalculated if the
value is reinserted.
A more efficient approach is to use internal iteration, that is,
map-like functions, which avoids unnecessary conversions when iterating,
and allows to use an efficient component-wise approach when merging.
2019-09-10 21:52:53 +03:00
Alexander Kuzmenkov
8e9a8584e0
Do not provide mutable key access in hash map cells.
...
We don't need it anymore after we changed the hash table key memory
management to use callbacks. Removing this interface is important for
hash maps that do not store the key, such as FixedHashMap or the
prospective compound StringHashMap.
2019-09-10 20:12:30 +03:00
Alexander Kuzmenkov
24a8755b82
Formatting changes for StringHashMap PR #5417 .
2019-08-28 13:52:14 +03:00
Alexander Kuzmenkov
011150fa8a
Make PairNoInit a simple struct.
2019-08-01 19:54:33 +03:00
Amos Bird
26ab5dd7a7
A Proper lookup table that uses HashTable's API
...
This is the first step of allowing heterogeneous cells in hash tables.
performance test results are
```
1. HashMap<UInt16, UInt8, TrivialHash, HashTableFixedGrower<16>>;
2. NewLookupMap<UInt16, UInt8>
ResolutionWidth 30000 1 .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................223550276.46
ResolutionWidth 30000 2 .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................248772721.24
Best: 2 - 24877272124
ResolutionWidth 100000 1 ..........................................................................................................................................................................................................................................................238498413.99
ResolutionWidth 100000 2 ..........................................................................................................................................................................................................................................................261808889.98
Best: 2 - 26180888998
ResolutionWidth 300000 1 ...................................................................................239307348.81
ResolutionWidth 300000 2 ...................................................................................257592761.30
Best: 2 - 25759276130
ResolutionWidth 1000000 1 .........................240144759.26
ResolutionWidth 1000000 2 .........................257093531.91
Best: 2 - 25709353191
ResolutionWidth 5000000 1 .....241573260.35
ResolutionWidth 5000000 2 .....259314162.79
Best: 2 - 25931416279
ResolutionDepth 30000 1 .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................217108119.84
ResolutionDepth 30000 2 .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................249459504.41
Best: 2 - 24945950441
ResolutionDepth 100000 1 ..........................................................................................................................................................................................................................................................229065162.17
ResolutionDepth 100000 2 ..........................................................................................................................................................................................................................................................253769105.64
Best: 2 - 25376910564
ResolutionDepth 300000 1 ...................................................................................233079225.18
ResolutionDepth 300000 2 ...................................................................................256316273.78
Best: 2 - 25631627378
ResolutionDepth 1000000 1 .........................234184633.51
ResolutionDepth 1000000 2 .........................261100491.57
Best: 2 - 26110049157
ResolutionDepth 5000000 1 .....233118795.66
ResolutionDepth 5000000 2 .....252436160.41
Best: 2 - 25243616041
```
2019-03-01 16:47:13 +08:00
Nikolai Kochetov
01209533f7
Optimize reverse index for ColumnUnique.
2018-08-07 21:10:16 +03:00
Alexey Milovidov
1a6cb2989b
Better [#CLICKHOUSE-2].
2017-12-01 21:36:55 +03:00
Alexey Milovidov
8e5f92f025
Fixed translation errors, part 1 [#CLICKHOUSE-3].
2017-05-09 15:07:35 -04:00
f1yegor
46db454562
translate comments
2017-05-09 13:03:35 -04:00
Alexey Milovidov
310736cd7e
Moved headers and sources to same place [#CLICKHOUSE-3].
2017-04-01 12:22:42 +03:00
