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add example with file globbing
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@ -91,11 +91,11 @@ INSERT INTO t FORMAT TabSeparated
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You can insert data separately from the query by using the command-line client or the HTTP interface. For more information, see the section “[Interfaces](../../interfaces)”.
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### Constraints
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## Constraints
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If table has [constraints](../../sql-reference/statements/create/table.md#constraints), their expressions will be checked for each row of inserted data. If any of those constraints is not satisfied — server will raise an exception containing constraint name and expression, the query will be stopped.
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### Inserting the Results of `SELECT`
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## Inserting the Results of `SELECT`
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**Syntax**
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@ -114,7 +114,7 @@ However, you can delete old data using `ALTER TABLE ... DROP PARTITION`.
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To insert a default value instead of `NULL` into a column with not nullable data type, enable [insert_null_as_default](../../operations/settings/settings.md#insert_null_as_default) setting.
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### Inserting Data from a File
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## Inserting Data from a File
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**Syntax**
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@ -122,14 +122,15 @@ To insert a default value instead of `NULL` into a column with not nullable data
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INSERT INTO [db.]table [(c1, c2, c3)] FROM INFILE file_name [COMPRESSION type] FORMAT format_name
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```
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Use the syntax above to insert data from a file stored on a **client** side. `file_name` and `type` are string literals. Input file [format](../../interfaces/formats.md) must be set in the `FORMAT` clause.
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Use the syntax above to insert data from a file, or files, stored on the **client** side. `file_name` and `type` are string literals. Input file [format](../../interfaces/formats.md) must be set in the `FORMAT` clause.
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Compressed files are supported. Compression type is detected by the extension of the file name. Or it can be explicitly specified in a `COMPRESSION` clause. Supported types are: `'none'`, `'gzip'`, `'deflate'`, `'br'`, `'xz'`, `'zstd'`, `'lz4'`, `'bz2'`.
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Compressed files are supported. The compression type is detected by the extension of the file name. Or it can be explicitly specified in a `COMPRESSION` clause. Supported types are: `'none'`, `'gzip'`, `'deflate'`, `'br'`, `'xz'`, `'zstd'`, `'lz4'`, `'bz2'`.
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This functionality is available in the [command-line client](../../interfaces/cli.md) and [clickhouse-local](../../operations/utilities/clickhouse-local.md).
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**Example**
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**Examples**
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### Single file with FROM INFILE
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Execute the following queries using [command-line client](../../interfaces/cli.md):
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```bash
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@ -148,7 +149,18 @@ Result:
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└────┴──────┘
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```
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### Inserting into Table Function
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### Multiple files with FROM INFILE using globs
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This example is very similar to the previous one but inserts from multiple files using `FROM INFILE 'input_*.csv`.
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```bash
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echo 1,A > input_1.csv ; echo 2,B > input_2.csv
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clickhouse-client --query="CREATE TABLE infile_globs (id UInt32, text String) ENGINE=MergeTree() ORDER BY id;"
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clickhouse-client --query="INSERT INTO infile_globs FROM INFILE 'input_*.csv' FORMAT CSV;"
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clickhouse-client --query="SELECT * FROM infile_globs FORMAT PrettyCompact;"
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```
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## Inserting into Table Function
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Data can be inserted into tables referenced by [table functions](../../sql-reference/table-functions/index.md).
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@ -176,7 +188,7 @@ Result:
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└─────┴───────────────────────┘
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```
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### Performance Considerations
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## Performance Considerations
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`INSERT` sorts the input data by primary key and splits them into partitions by a partition key. If you insert data into several partitions at once, it can significantly reduce the performance of the `INSERT` query. To avoid this:
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