Local Files / Directories¶
Files can be queried directly by enclosing the file, directory name
or a remote location in single '
quotes as shown in the examples.
Create a CSV file to query.
$ echo "a,b" > data.csv
$ echo "1,2" >> data.csv
Query that single file (the CLI also supports parquet, compressed csv, avro, json and more)
$ datafusion-cli
DataFusion CLI v17.0.0
> select * from 'data.csv';
+---+---+
| a | b |
+---+---+
| 1 | 2 |
+---+---+
1 row in set. Query took 0.007 seconds.
You can also query directories of files with compatible schemas:
$ ls data_dir/
data.csv data2.csv
$ datafusion-cli
DataFusion CLI v16.0.0
> select * from 'data_dir';
+---+---+
| a | b |
+---+---+
| 3 | 4 |
| 1 | 2 |
+---+---+
2 rows in set. Query took 0.007 seconds.
Remote Files / Directories¶
You can also query directly any remote location supported by DataFusion without registering the location as a table. For example, to read from a remote parquet file via HTTP(S) you can use the following:
select count(*) from 'https://datasets.clickhouse.com/hits_compatible/athena_partitioned/hits_1.parquet'
+----------+
| COUNT(*) |
+----------+
| 1000000 |
+----------+
1 row in set. Query took 0.595 seconds.
To read from an AWS S3 or GCS, use s3
or gs
as a protocol prefix. For
example, to read a file in an S3 bucket named my-data-bucket
use the URL
s3://my-data-bucket
and set the relevant access credentials as environmental
variables (e.g. for AWS S3 you need to at least AWS_ACCESS_KEY_ID
and
AWS_SECRET_ACCESS_KEY
).
select count(*) from 's3://my-data-bucket/athena_partitioned/hits.parquet'
See the CREATE EXTERNAL TABLE
section for
additional configuration options.
CREATE EXTERNAL TABLE
¶
It is also possible to create a table backed by files or remote locations via
CREATE EXTERNAL TABLE
as shown below. Note that wildcards (e.g. *
) are also
supported
For example, to create a table hits
backed by a local parquet file, use:
CREATE EXTERNAL TABLE hits
STORED AS PARQUET
LOCATION 'hits.parquet';
To create a table hits
backed by a remote parquet file via HTTP(S), use
CREATE EXTERNAL TABLE hits
STORED AS PARQUET
LOCATION 'https://datasets.clickhouse.com/hits_compatible/athena_partitioned/hits_1.parquet';
In both cases, hits
now can be queried as a regular table:
select count(*) from hits;
+----------+
| COUNT(*) |
+----------+
| 1000000 |
+----------+
1 row in set. Query took 0.344 seconds.
Formats¶
Parquet¶
The schema information for parquet will be derived automatically.
Register a single file parquet datasource
CREATE EXTERNAL TABLE taxi
STORED AS PARQUET
LOCATION '/mnt/nyctaxi/tripdata.parquet';
Register a single folder parquet datasource. Note: All files inside must be valid parquet files and have compatible schemas
CREATE EXTERNAL TABLE taxi
STORED AS PARQUET
LOCATION '/mnt/nyctaxi/';
Register a single folder parquet datasource by specifying a wildcard for files to read
CREATE EXTERNAL TABLE taxi
STORED AS PARQUET
LOCATION '/mnt/nyctaxi/*.parquet';
CSV¶
DataFusion will infer the CSV schema automatically or you can provide it explicitly.
Register a single file csv datasource with a header row.
CREATE EXTERNAL TABLE test
STORED AS CSV
LOCATION '/path/to/aggregate_test_100.csv'
OPTIONS ('has_header' 'true');
Register a single file csv datasource with explicitly defined schema.
CREATE EXTERNAL TABLE test (
c1 VARCHAR NOT NULL,
c2 INT NOT NULL,
c3 SMALLINT NOT NULL,
c4 SMALLINT NOT NULL,
c5 INT NOT NULL,
c6 BIGINT NOT NULL,
c7 SMALLINT NOT NULL,
c8 INT NOT NULL,
c9 BIGINT NOT NULL,
c10 VARCHAR NOT NULL,
c11 FLOAT NOT NULL,
c12 DOUBLE NOT NULL,
c13 VARCHAR NOT NULL
)
STORED AS CSV
LOCATION '/path/to/aggregate_test_100.csv';
Locations¶
HTTP(s)¶
To read from a remote parquet file via HTTP(S) you can use the following:
CREATE EXTERNAL TABLE hits
STORED AS PARQUET
LOCATION 'https://datasets.clickhouse.com/hits_compatible/athena_partitioned/hits_1.parquet';
S3¶
AWS S3 data sources must have connection credentials configured.
To create an external table from a file in an S3 bucket:
CREATE EXTERNAL TABLE test
STORED AS PARQUET
OPTIONS(
'aws.access_key_id' '******',
'aws.secret_access_key' '******',
'aws.region' 'us-east-2'
)
LOCATION 's3://bucket/path/file.parquet';
It is also possible to specify the access information using environment variables:
$ export AWS_DEFAULT_REGION=us-east-2
$ export AWS_SECRET_ACCESS_KEY=******
$ export AWS_ACCESS_KEY_ID=******
$ datafusion-cli
`datafusion-cli v21.0.0
> create external table test stored as parquet location 's3://bucket/path/file.parquet';
0 rows in set. Query took 0.374 seconds.
> select * from test;
+----------+----------+
| column_1 | column_2 |
+----------+----------+
| 1 | 2 |
+----------+----------+
1 row in set. Query took 0.171 seconds.
Supported configuration options are:
Environment Variable |
Configuration Option |
Description |
---|---|---|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
See IAM Roles |
|
|
set to “true” to permit HTTP connections without TLS |
|
|
Support for using a named profile to supply credentials |
OSS¶
Alibaba cloud OSS data sources must have connection credentials configured
CREATE EXTERNAL TABLE test
STORED AS PARQUET
OPTIONS(
'aws.access_key_id' '******',
'aws.secret_access_key' '******',
'aws.oss.endpoint' 'https://bucket.oss-cn-hangzhou.aliyuncs.com'
)
LOCATION 'oss://bucket/path/file.parquet';
The supported OPTIONS are
access_key_id
secret_access_key
endpoint
Note that the endpoint
format of oss needs to be: https://{bucket}.{oss-region-endpoint}
COS¶
Tencent cloud COS data sources data sources must have connection credentials configured
CREATE EXTERNAL TABLE test
STORED AS PARQUET
OPTIONS(
'aws.access_key_id' '******',
'aws.secret_access_key' '******',
'aws.cos.endpoint' 'https://cos.ap-singapore.myqcloud.com'
)
LOCATION 'cos://bucket/path/file.parquet';
The supported OPTIONS are:
access_key_id
secret_access_key
endpoint
Note that the endpoint
format of urls must be: https://cos.{cos-region-endpoint}
GCS¶
Google Cloud Storage data sources must have connection credentials configured
For example, to create an external table from a file in a GCS bucket
CREATE EXTERNAL TABLE test
STORED AS PARQUET
OPTIONS(
'gcp.service_account_path' '/tmp/gcs.json',
)
LOCATION 'gs://bucket/path/file.parquet';
It is also possible to specify the access information using environment variables:
$ export GOOGLE_SERVICE_ACCOUNT=/tmp/gcs.json
$ datafusion-cli
DataFusion CLI v21.0.0
> create external table test stored as parquet location 'gs://bucket/path/file.parquet';
0 rows in set. Query took 0.374 seconds.
> select * from test;
+----------+----------+
| column_1 | column_2 |
+----------+----------+
| 1 | 2 |
+----------+----------+
1 row in set. Query took 0.171 seconds.
Supported configuration options are:
Environment Variable |
Configuration Option |
Description |
---|---|---|
|
|
location of service account file |
|
|
(alias) location of service account file |
|
|
(alias) location of service account file |
|
|
JSON serialized service account key |
|
|
location of application credentials file |
|
bucket name |
|
|
(alias) bucket name |