Golang SQL database driver for ClickHouse.
There are two version of this driver, v1 and v2, available as separate branches.
v1 is now in a state of a maintenance - we will only accept PRs for bug and security fixes.
Users should use v2 which is production ready and significantly faster than v1.
- Uses native ClickHouse TCP client-server protocol
- Compatibility with
database/sql
(slower than native interface!) - Marshal rows into structs (ScanStruct, Select)
- Unmarshal struct to row (AppendStruct)
- Connection pool
- Failover and load balancing
- Bulk write support (for
database/sql
usebegin->prepare->(in loop exec)->commit
) - AsyncInsert
- Named and numeric placeholders support
- LZ4 compression support
- External data
Support for the ClickHouse protocol advanced features using Context
:
- Query ID
- Quota Key
- Settings
- OpenTelemetry
- Execution events:
- Logs
- Progress
- Profile info
- Profile events
conn := clickhouse.OpenDB(&clickhouse.Options{
Addr: []string{"127.0.0.1:9999"},
Auth: clickhouse.Auth{
Database: "default",
Username: "default",
Password: "",
},
TLS: &tls.Config{
InsecureSkipVerify: true,
},
Settings: clickhouse.Settings{
"max_execution_time": 60,
},
DialTimeout: 5 * time.Second,
Compression: &clickhouse.Compression{
clickhouse.CompressionLZ4,
},
Debug: true,
})
conn.SetMaxIdleConns(5)
conn.SetMaxOpenConns(10)
conn.SetConnMaxLifetime(time.Hour)
- hosts - comma-separated list of single address hosts for load-balancing and failover
- username/password - auth credentials
- database - select the current default database
- dial_timeout - a duration string is a possibly signed sequence of decimal numbers, each with optional fraction and a unit suffix such as "300ms", "1s". Valid time units are "ms", "s", "m".
- connection_open_strategy - random/in_order (default random).
- round-robin - choose a round-robin server from the set
- in_order - first live server is chosen in specified order
- debug - enable debug output (boolean value)
- compress - enable lz4 compression (boolean value)
SSL/TLS parameters:
- secure - establish secure connection (default is false)
- skip_verify - skip certificate verification (default is false)
Example:
clickhouse://username:password@host1:9000,host2:9000/database?dial_timeout=200ms&max_execution_time=60
V1 (READ) | V2 (READ) std | V2 (READ) native |
---|---|---|
1.218s | 924.390ms | 675.721ms |
V1 (WRITE) | V2 (WRITE) std | V2 (WRITE) native | V2 (WRITE) by column |
---|---|---|---|
1.899s | 1.177s | 699.203ms | 661.973ms |
go get -u github.com/ClickHouse/clickhouse-go/v2
At a low level all driver connect methods (DSN/OpenDB/Open) will use the Go tls package to establish a secure connection. The driver knows to use TLS if the Options struct contains a non-nil tls.Config pointer.
Setting secure in the DSN creates a minimal tls.Config struct with only the InsecureSkipVerify field set (either true or false). It is equivalent to this code:
conn := clickhouse.OpenDB(&clickhouse.Options{
...
TLS: &tls.Config{
InsecureSkipVerify: false
}
...
})
This minimal tls.Config is normally all that is necessary to connect to the secure native port (normally 9440) on a ClickHouse server. If the ClickHouse server does not have a valid certificate (expired, wrong host name, not signed by a publicly recognized root Certificate Authority), InsecureSkipVerify can be to true
, but that is strongly discouraged.
If additional TLS parameters are necessary the application code should set the desired fields in the tls.Config struct. That can include specific cipher suites, forcing a particular TLS version (like 1.2 or 1.3), adding an internal CA certificate chain, adding a client certificate (and private key) if required by the ClickHouse server, and most of the other options that come with a more specialized security setup.
-
Database drivers
- mailru/go-clickhouse (uses the HTTP protocol)
- uptrace/go-clickhouse (uses the native TCP protocol with
database/sql
-like API) - drivers with columnar interface :
-
Insert collectors: