Export and import
You use the ycqlsh
script to export and import YCQL data. For details on how to use the script to connect to a YugabyteDB cluster, as well as the full list of available options, see ycqlsh reference.
Export schema
You use the DESCRIBE
command (abbreviated to DESC
) to export the schema.
To export the schema of a single keyspace, run the following command:
./bin/ycqlsh -e "DESC KEYSPACE <keyspace_name>" > <file>
- keyspace_name is the name of the keyspace to be exported.
- file is the path to the resulting CQL script file.
To export the schema of every keyspace, run the following command:
ycqlsh -e "DESC SCHEMA" > <file>
file is the path to the resulting CQL script file.
Export data
To export your data, use the COPY TO
command that queries all rows of the specified table and writes into a comma-separated values (CSV) file.
The following is a full syntax of the COPY TO
command:
COPY table_name [( column_list )]
TO 'file_name'[, 'file2_name', ...] | STDIN
[WITH option = 'value' [AND ...]]
- table_name is the name of the table to be exported.
- column_list is an optional comma-separated list of column names.
- file_name is the name of the file to which to export the data.
The command supports multiple options. The following table outlines some of the more commonly used ones.
Option | Description | Default value |
---|---|---|
DELIMITER |
Field separator character. | , (comma) |
HEADER |
If true, output column names as the first row of data. | false |
PAGESIZE |
Page size for fetching results. | 1000 |
PAGETIMEOUT |
Page timeout for fetching results. | 10 |
MAXREQUESTS |
Maximum number of requests each worker processes in parallel. | 6 |
MAXOUTPUTSIZE |
Maximum number of lines in the output file. When set, the output file is split into segments no larger than this value. Use -1 for no maximum. |
-1 |
Import schema
To import a schema, use the SOURCE
command, as follows:
ycqlsh -e "SOURCE '<file>'"
file is the path to the CQL script file from which to import the schema.
Import data
After you import the schema, use the COPY FROM
command to import the actual data from one or more CSV files.
The following is a full syntax of the COPY FROM
command:
COPY table_name [( column_list )]
FROM 'file_name'[, 'file2_name', ...] | STDIN
[WITH option = 'value' [AND ...]]
- table_name is the name of the destination table.
- column_list is an optional comma-separated list of column names.
- file_name is the name of the file from which to import the data.
The following table lists commonly-used options.
Option | Description | Default |
---|---|---|
DELIMITER |
Field separator character. | , (comma) |
HEADER |
If true, the first row of data contains column names. | false |
CHUNKSIZE |
Maximum number of rows each insert. | 1000 |
INGESTRATE |
Desired ingestion rate in rows per second. Must be greater than CHUNKSIZE . |
100000 |