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Merge pull request #44795 from ClickHouse/Avogar-patch-2

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Fix incorrect docs
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Dan Roscigno 2022-12-30 18:43:56 -05:00 committed by GitHub
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1 changed files with 8 additions and 5 deletions
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docs/en/interfaces/schema-inference.md
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@ -1050,14 +1050,14 @@ SETTINGS schema_inference_hints = 'age LowCardinality(UInt8), status Nullable(St
### schema_inference_make_columns_nullable
Controls making inferred types `Nullable` in schema inference for formats without information about nullability.
If the setting is enabled, the inferred type will be `Nullable` only if the column contains `NULL` in a sample that is parsed during schema inference.
If the setting is enabled, all inferred type will be `Nullable`, if disabled, the inferred type will be `Nullable` only if the column contains `NULL` in a sample that is parsed during schema inference.
Enabled by default.
**Examples**
```sql
SET schema_inference_make_columns_nullable = 0
SET schema_inference_make_columns_nullable = 1
DESC format(JSONEachRow, $$
{"id" : 1, "age" : 25, "name" : "Josh", "status" : null, "hobbies" : ["football", "cooking"]}
{"id" : 2, "age" : 19, "name" : "Alan", "status" : "married", "hobbies" : ["tennis", "art"]}
@ -1071,12 +1071,15 @@ DESC format(JSONEachRow, $$
│ status │ Nullable(String) │ │ │ │ │ │
│ hobbies │ Array(Nullable(String)) │ │ │ │ │ │
└─────────┴─────────────────────────┴──────────────┴────────────────────┴─────────┴──────────────────┴────────────────┘
```
```sql
SET schema_inference_make_columns_nullable = 0
DESC format(JSONEachRow, $$
{"id" : 1, "age" : 25, "name" : "Josh", "status" : null, "hobbies" : ["football", "cooking"]}
{"id" : 2, "age" : 19, "name" : "Alan", "status" : "married", "hobbies" : ["tennis", "art"]}
$$)
```
```response
┌─name────┬─type─────────────┬─default_type─┬─default_expression─┬─comment─┬─codec_expression─┬─ttl_expression─┐
│ id │ Int64 │ │ │ │ │ │