README.md
1[](https://godoc.org/github.com/jackc/pgx)
2[](https://travis-ci.org/jackc/pgx)
3
4# pgx - PostgreSQL Driver and Toolkit
5
6pgx is a pure Go driver and toolkit for PostgreSQL. pgx is different from other drivers such as [pq](http://godoc.org/github.com/lib/pq) because, while it can operate as a database/sql compatible driver, pgx is also usable directly. It offers a native interface similar to database/sql that offers better performance and more features.
7
8
9```go
10var name string
11var weight int64
12err := conn.QueryRow("select name, weight from widgets where id=$1", 42).Scan(&name, &weight)
13if err != nil {
14 return err
15}
16```
17
18## Features
19
20pgx supports many additional features beyond what is available through database/sql.
21
22* Support for approximately 60 different PostgreSQL types
23* Batch queries
24* Single-round trip query mode
25* Full TLS connection control
26* Binary format support for custom types (can be much faster)
27* Copy protocol support for faster bulk data loads
28* Extendable logging support including built-in support for log15 and logrus
29* Connection pool with after connect hook to do arbitrary connection setup
30* Listen / notify
31* PostgreSQL array to Go slice mapping for integers, floats, and strings
32* Hstore support
33* JSON and JSONB support
34* Maps inet and cidr PostgreSQL types to net.IPNet and net.IP
35* Large object support
36* NULL mapping to Null* struct or pointer to pointer.
37* Supports database/sql.Scanner and database/sql/driver.Valuer interfaces for custom types
38* Logical replication connections, including receiving WAL and sending standby status updates
39* Notice response handling (this is different than listen / notify)
40
41## Performance
42
43pgx performs roughly equivalent to [go-pg](https://github.com/go-pg/pg) and is almost always faster than [pq](http://godoc.org/github.com/lib/pq). When parsing large result sets the percentage difference can be significant (16483 queries/sec for pgx vs. 10106 queries/sec for pq -- 63% faster).
44
45In many use cases a significant cause of latency is network round trips between the application and the server. pgx supports query batching to bundle multiple queries into a single round trip. Even in the case of a connection with the lowest possible latency, a local Unix domain socket, batching as few as three queries together can yield an improvement of 57%. With a typical network connection the results can be even more substantial.
46
47See this [gist](https://gist.github.com/jackc/4996e8648a0c59839bff644f49d6e434) for the underlying benchmark results or checkout [go_db_bench](https://github.com/jackc/go_db_bench) to run tests for yourself.
48
49In addition to the native driver, pgx also includes a number of packages that provide additional functionality.
50
51## github.com/jackc/pgx/stdlib
52
53database/sql compatibility layer for pgx. pgx can be used as a normal database/sql driver, but at any time the native interface may be acquired for more performance or PostgreSQL specific functionality.
54
55## github.com/jackc/pgx/pgtype
56
57Approximately 60 PostgreSQL types are supported including uuid, hstore, json, bytea, numeric, interval, inet, and arrays. These types support database/sql interfaces and are usable even outside of pgx. They are fully tested in pgx and pq. They also support a higher performance interface when used with the pgx driver.
58
59## github.com/jackc/pgx/pgproto3
60
61pgproto3 provides standalone encoding and decoding of the PostgreSQL v3 wire protocol. This is useful for implementing very low level PostgreSQL tooling.
62
63## github.com/jackc/pgx/pgmock
64
65pgmock offers the ability to create a server that mocks the PostgreSQL wire protocol. This is used internally to test pgx by purposely inducing unusual errors. pgproto3 and pgmock together provide most of the foundational tooling required to implement a PostgreSQL proxy or MitM (such as for a custom connection pooler).
66
67## Documentation
68
69pgx includes extensive documentation in the godoc format. It is viewable online at [godoc.org](https://godoc.org/github.com/jackc/pgx).
70
71## Testing
72
73pgx supports multiple connection and authentication types. Setting up a test
74environment that can test all of them can be cumbersome. In particular,
75Windows cannot test Unix domain socket connections. Because of this pgx will
76skip tests for connection types that are not configured.
77
78### Normal Test Environment
79
80To setup the normal test environment, first install these dependencies:
81
82 go get github.com/cockroachdb/apd
83 go get github.com/hashicorp/go-version
84 go get github.com/jackc/fake
85 go get github.com/lib/pq
86 go get github.com/pkg/errors
87 go get github.com/satori/go.uuid
88 go get github.com/shopspring/decimal
89 go get github.com/sirupsen/logrus
90 go get go.uber.org/zap
91 go get gopkg.in/inconshreveable/log15.v2
92
93Then run the following SQL:
94
95 create user pgx_md5 password 'secret';
96 create user " tricky, ' } "" \ test user " password 'secret';
97 create database pgx_test;
98 create user pgx_replication with replication password 'secret';
99
100Connect to database pgx_test and run:
101
102 create extension hstore;
103 create domain uint64 as numeric(20,0);
104
105Next open conn_config_test.go.example and make a copy without the
106.example. If your PostgreSQL server is accepting connections on 127.0.0.1,
107then you are done.
108
109### Connection and Authentication Test Environment
110
111Complete the normal test environment setup and also do the following.
112
113Run the following SQL:
114
115 create user pgx_none;
116 create user pgx_pw password 'secret';
117
118Add the following to your pg_hba.conf:
119
120If you are developing on Unix with domain socket connections:
121
122 local pgx_test pgx_none trust
123 local pgx_test pgx_pw password
124 local pgx_test pgx_md5 md5
125
126If you are developing on Windows with TCP connections:
127
128 host pgx_test pgx_none 127.0.0.1/32 trust
129 host pgx_test pgx_pw 127.0.0.1/32 password
130 host pgx_test pgx_md5 127.0.0.1/32 md5
131
132### Replication Test Environment
133
134Add a replication user:
135
136 create user pgx_replication with replication password 'secret';
137
138Add a replication line to your pg_hba.conf:
139
140 host replication pgx_replication 127.0.0.1/32 md5
141
142Change the following settings in your postgresql.conf:
143
144 wal_level=logical
145 max_wal_senders=5
146 max_replication_slots=5
147
148Set `replicationConnConfig` appropriately in `conn_config_test.go`.
149
150## Version Policy
151
152pgx follows semantic versioning for the documented public API on stable releases. Branch `v3` is the latest stable release. `master` can contain new features or behavior that will change or be removed before being merged to the stable `v3` branch (in practice, this occurs very rarely). `v2` is the previous stable release.
153
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