thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-09-20 08:40:50 +00:00
Code Issues Packages Projects Releases Wiki Activity

Docs: fix docs of EXPLAIN PLAN indexes=1

Browse Source
This commit is contained in:
Robert Schulze 2023-01-25 11:02:50 +00:00
parent f818e3070d
commit da7a657f1f
No known key found for this signature in database
GPG Key ID: 26703B55FB13728A
2 changed files with 28 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
docs/en/sql-reference/statements/explain.md
View File

@ -276,14 +276,12 @@ EXPLAIN json = 1, description = 0, header = 1 SELECT 1, 2 + dummy;
With `indexes` = 1, the `Indexes` key is added. It contains an array of used indexes. Each index is described as JSON with `Type` key (a string `MinMax`, `Partition`, `PrimaryKey` or `Skip`) and optional keys:
- `Name` — An index name (for now, is used only for `Skip` index).
- `Keys` — An array of columns used by the index.
- `Condition` — A string with condition used.
- `Description` — An index (for now, is used only for `Skip` index).
- `Initial Parts` — A number of parts before the index is applied.
- `Selected Parts` — A number of parts after the index is applied.
- `Initial Granules` — A number of granules before the index is applied.
- `Selected Granulesis` — A number of granules after the index is applied.
- `Name` — The index name (currently only used for `Skip` indexes).
- `Keys` — The array of columns used by the index.
- `Condition` — The used condition.
- `Description` — The index description (currently only used for `Skip` indexes).
- `Parts` — The number of parts before/after the index is applied.
- `Granules` — The number of granules before/after the index is applied.
Example:
@ -294,46 +292,36 @@ Example:
"Type": "MinMax",
"Keys": ["y"],
"Condition": "(y in [1, +inf))",
"Initial Parts": 5,
"Selected Parts": 4,
"Initial Granules": 12,
"Selected Granules": 11
"Parts": 5/4,
"Granules": 12/11
},
{
"Type": "Partition",
"Keys": ["y", "bitAnd(z, 3)"],
"Condition": "and((bitAnd(z, 3) not in [1, 1]), and((y in [1, +inf)), (bitAnd(z, 3) not in [1, 1])))",
"Initial Parts": 4,
"Selected Parts": 3,
"Initial Granules": 11,
"Selected Granules": 10
"Parts": 4/3,
"Granules": 11/10
},
{
"Type": "PrimaryKey",
"Keys": ["x", "y"],
"Condition": "and((x in [11, +inf)), (y in [1, +inf)))",
"Initial Parts": 3,
"Selected Parts": 2,
"Initial Granules": 10,
"Selected Granules": 6
"Parts": 3/2,
"Granules": 10/6
},
{
"Type": "Skip",
"Name": "t_minmax",
"Description": "minmax GRANULARITY 2",
"Initial Parts": 2,
"Selected Parts": 1,
"Initial Granules": 6,
"Selected Granules": 2
"Parts": 2/1,
"Granules": 6/2
},
{
"Type": "Skip",
"Name": "t_set",
"Description": "set GRANULARITY 2",
"Initial Parts": 1,
"Selected Parts": 1,
"Initial Granules": 2,
"Selected Granules": 1
"": 1/1,
"Granules": 2/1
}
]
```

36
docs/ru/sql-reference/statements/explain.md
View File

@ -248,10 +248,8 @@ EXPLAIN json = 1, description = 0, header = 1 SELECT 1, 2 + dummy;
- `Keys` — массив столбцов, используемых индексом.
- `Condition` — строка с используемым условием.
- `Description` — индекс (на данный момент используется только для индекса `Skip`).
- `Initial Parts` — количество кусков до применения индекса.
- `Selected Parts` — количество кусков после применения индекса.
- `Initial Granules` — количество гранул до применения индекса.
- `Selected Granulesis` — количество гранул после применения индекса.
- `Parts` — количество кусков до/после применения индекса.
- `Granules` — количество гранул до/после применения индекса.
Пример:
@ -262,46 +260,36 @@ EXPLAIN json = 1, description = 0, header = 1 SELECT 1, 2 + dummy;
"Type": "MinMax",
"Keys": ["y"],
"Condition": "(y in [1, +inf))",
"Initial Parts": 5,
"Selected Parts": 4,
"Initial Granules": 12,
"Selected Granules": 11
"Parts": 5/4,
"Granules": 12/11
},
{
"Type": "Partition",
"Keys": ["y", "bitAnd(z, 3)"],
"Condition": "and((bitAnd(z, 3) not in [1, 1]), and((y in [1, +inf)), (bitAnd(z, 3) not in [1, 1])))",
"Initial Parts": 4,
"Selected Parts": 3,
"Initial Granules": 11,
"Selected Granules": 10
"Parts": 4/3,
"Granules": 11/10
},
{
"Type": "PrimaryKey",
"Keys": ["x", "y"],
"Condition": "and((x in [11, +inf)), (y in [1, +inf)))",
"Initial Parts": 3,
"Selected Parts": 2,
"Initial Granules": 10,
"Selected Granules": 6
"Parts": 3/2,
"Granules": 10/6
},
{
"Type": "Skip",
"Name": "t_minmax",
"Description": "minmax GRANULARITY 2",
"Initial Parts": 2,
"Selected Parts": 1,
"Initial Granules": 6,
"Selected Granules": 2
"Parts": 2/1,
"Granules": 6/2
},
{
"Type": "Skip",
"Name": "t_set",
"Description": "set GRANULARITY 2",
"Initial Parts": 1,
"Selected Parts": 1,
"Initial Granules": 2,
"Selected Granules": 1
"": 1/1,
"Granules": 2/1
}
]
```