README
¶
Apache Phoenix/Avatica SQL Driver
An Apache Phoenix/Avatica driver for Go's database/sql package
Getting started
Install using the go tool or your dependency management tool:
$ go get github.com/Boostport/avatica
Usage
The Phoenix/Avatica driver implements Go's database/sql/driver interface, so, import Go's
database/sql package and the driver:
import "database/sql"
import _ "github.com/Boostport/avatica"
db, err := sql.Open("avatica", "http://localhost:8765")
Then simply use the database connection to query some data, for example:
rows := db.Query("SELECT COUNT(*) FROM test")
DSN (Data Source Name)
The DSN has the following format (optional parts are marked by square brackets):
http://[username:password@]address:port[/schema][?parameter1=value&...parameterN=value]
In other words, the scheme (http), address and port is mandatory, but the schema and parameters are optional.
username
This is the JDBC username that is passed directly to the backing database. It is NOT used for authenticating against Avatica.
password
This is the JDBC password that is passed directly to the backing database. It is NOT used for authenticating against Avatica.
schema
The schema path sets the default schema to use for this connection. For example, if you set it to myschema,
then executing the query SELECT * FROM my_table will have the equivalence of SELECT * FROM myschema.my_table.
If schema is set, you can still work on tables in other schemas by supplying a schema prefix:
SELECT * FROM myotherschema.my_other_table.
The following parameters are supported:
authentication
The authentication type to use when authenticating against Avatica. Valid values are BASIC for HTTP Basic authentication,
DIGEST for HTTP Digest authentication, and SPNEGO for Kerberos with SPNEGO authentication.
avaticaUser
The user to use when authenticating against Avatica. This parameter is required if authentication is BASIC or DIGEST.
avaticaPassword
The password to use when authenticating against Avatica. This parameter is required if authentication is BASIC or DIGEST.
principal
The Kerberos principal to use when authenticating against Avatica. It should be in the form primary/instance@realm, where
the instance is optional. This parameter is required if authentication is SPNEGO and you want the driver to perform the
Kerberos login.
keytab
The path to the Kerberos keytab to use when authenticating against Avatica. This parameter is required if authentication
is SPNEGO and you want the driver to perform the Kerberos login.
krb5Conf
The path to the Kerberos configuration to use when authenticating against Avatica. This parameter is required if authentication
is SPNEGO and you want the driver to perform the Kerberos login.
krb5CredentialsCache
The path to the Kerberos credential cache file to use when authenticating against Avatica. This parameter is required if
authentication is SPNEGO and you have logged into Kerberos already and want the driver to use the existing credentials.
location
The location will be set as the location of unserialized time.Time values. It must be a valid timezone.
If you want to use the local timezone, use Local. By default, this is set to UTC.
maxRowsTotal
The maxRowsTotal parameter sets the maximum number of rows to return for a given query. By default, this is set to
-1, so that there is no limit on the number of rows returned.
frameMaxSize
The frameMaxSize parameter sets the maximum number of rows to return in a frame. Depending on the number of rows
returned and subject to the limits of maxRowsTotal, a query result set can contain rows in multiple frames. These
additional frames are then fetched on a as-needed basis. frameMaxSize allows you to control the number of rows
in each frame to suit your application's performance profile. By default this is set to -1, so that there is no limit
on the number of rows in a frame.
transactionIsolation
Setting transactionIsolation allows you to set the isolation level for transactions using the connection. The value
should be a positive integer analogous to the transaction levels defined by the JDBC specification. The default value
is 0, which means transactions are not supported. This is to deal with the fact that Calcite/Avatica works with
many types of backends, with some backends having no transaction support. If you are using Apache Phoenix 4.7 onwards,
we recommend setting it to 4, which is the maximum isolation level supported.
The supported values for transactionIsolation are:
| Value | JDBC Constant | Description |
|---|---|---|
| 0 | none | Transactions are not supported |
| 1 | TRANSACTION_READ_UNCOMMITTED |
Dirty reads, non-repeatable reads and phantom reads may occur. |
| 2 | TRANSACTION_READ_COMMITTED |
Dirty reads are prevented, but non-repeatable reads and phantom reads may occur. |
| 4 | TRANSACTION_REPEATABLE_READ |
Dirty reads and non-repeatable reads are prevented, but phantom reads may occur. |
| 8 | TRANSACTION_SERIALIZABLE |
Dirty reads, non-repeatable reads, and phantom reads are all prevented. |
time.Time support
The following Phoenix/Avatica datatypes are automatically converted to and from time.Time:
TIME, DATE and TIMESTAMP.
It is important to understand that avatica and the underlying database ignores the timezone. If you save a time.Time
to the database, the timezone is ignored and vice-versa. This is why you need to make sure the location parameter
in your DSN is set to the same value as the location of the time.Time values you are inserting into the database.
We recommend using UTC, which is the default value of location.
Version compatibility
| Driver Version | Phoenix Version | Calcite-Avatica Version |
|---|---|---|
| 1.x.x | >= 4.8.0 | >= 1.8.0 |
| 2.x.x | >= 4.8.0 | >= 1.8.0 |
Development
To run tests, but skip tests in the vendor directory, run:
go test $(go list ./... | grep -v /vendor/)
The driver is not feature-complete yet, so contributions are very appreciated.
Updating protocol buffer definitions
To update the procotol buffer definitions, update CALCITE_VER in gen-protobuf.bat and gen-protobuf.sh to match
the version included by Phoenix and then run the appropriate script for your platform.
About the moby.yml file
The moby.yml file is used by our internal tool to automatically reload and test the code during development. We hope to have this tool open-sourced soon.
License
The driver is licensed under the Apache 2 license.
Documentation
¶
Overview ¶
Package avatica provides an Apache Phoenix Query Server/Avatica driver for Go's database/sql package.
Quickstart ¶
Import the database/sql package along with the avatica driver.
import "database/sql"
import _ "github.com/Boostport/avatica"
db, err := sql.Open("avatica", "http://phoenix-query-server:8765")
See https://github.com/Boostport/avatica#usage for more details
Index ¶
Constants ¶
const ( Eunknown int8 = iota Efatal Eerror Ewarning )
Error severity codes
Variables ¶
This section is empty.
Functions ¶
func NewHTTPClient ¶
NewHTTPClient creates a new httpClient from a host.
Types ¶
type Config ¶
type Config struct {
// contains filtered or unexported fields
}
Config is a configuration parsed from a DSN string
type ErrorCode ¶
type ErrorCode uint32
ErrorCode represents the error code returned by the avatica server
type RPCMetadata ¶
type RPCMetadata struct {
ServerAddress string
}
RPCMetadata contains metadata about the call that caused the error.
type ResponseError ¶
type ResponseError struct {
Exceptions []string
HasExceptions bool
ErrorMessage string
Severity int8
ErrorCode ErrorCode
SqlState SQLState
Metadata *RPCMetadata
}
ResponseError is an error type that contains detailed information on what caused the server to return an error.
func (ResponseError) Error ¶
func (r ResponseError) Error() string
func (ResponseError) Name ¶
func (r ResponseError) Name() string
Name returns the name of the error encountered by the server.
Source Files
Directories