Connection String Parameters
To connect to a database, the application provides a connection string which specifies parameters such as the host, the username, the password, etc. Connection strings have the form keyword1=value; keyword2=value; and are case-insensitive. Values containing special characters (e.g. semicolons) can be double-quoted. For more information, see the official doc page on connection strings.
Below are the connection string parameters which Npgsql understands.
Basic Connection
| Parameter |
Description |
Default |
| Host |
Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix-domain socket (specifying a Port is still required). |
Required |
| Port |
The TCP port of the PostgreSQL server. |
5432 |
| Database |
The PostgreSQL database to connect to. |
Same as Username |
| Username |
The username to connect with. Not required if using IntegratedSecurity. |
|
| Password |
The password to connect with. Not required if using IntegratedSecurity. |
|
| Passfile |
Path to a PostgreSQL password file (PGPASSFILE), from which the password is taken. |
|
Security and Encryption
| Parameter |
Description |
Default |
| SSL Mode |
Controls whether SSL is used, depending on server support. Can be Require, Disable, or Prefer. See docs for more info. |
Disable |
| Trust Server Certificate |
Whether to trust the server certificate without validating it. See docs for more info. |
false |
| Use SSL Stream |
Npgsql uses its own internal implementation of TLS/SSL. Turn this on to use .NET SslStream instead. |
false |
| Check Certificate Revocation |
Whether to check the certificate revocation list during authentication. False by default. |
false |
| Integrated Security |
Whether to use integrated security to log in (GSS/SSPI), currently supported on Windows only. See docs for more info. |
false |
| Persist Security Info |
Gets or sets a Boolean value that indicates if security-sensitive information, such as the password, is not returned as part of the connection if the connection is open or has ever been in an open state. Since 3.1 only. |
false |
| Kerberos Service Name |
The Kerberos service name to be used for authentication. See docs for more info. |
postgres |
| Include Realm |
The Kerberos realm to be used for authentication. See docs for more info. |
|
Pooling
| Parameter |
Description |
Default |
| Pooling |
Whether connection pooling should be used. |
true |
| Minimum Pool Size |
The minimum connection pool size. |
1 |
| Maximum Pool Size |
The maximum connection pool size. |
100 since 3.1, 20 previously |
| Connection Idle Lifetime |
The time (in seconds) to wait before closing idle connections in the pool if the count of all connections exceeds MinPoolSize. Since 3.1 only. |
300 |
| Connection Pruning Interval |
How many seconds the pool waits before attempting to prune idle connections that are beyond idle lifetime (see ConnectionIdleLifetime). Since 3.1 only. |
10 |
Timeouts and Keepalive
| Parameter |
Description |
Default |
| Timeout |
The time to wait (in seconds) while trying to establish a connection before terminating the attempt and generating an error. |
15 |
| Command Timeout |
The time to wait (in seconds) while trying to execute a command before terminating the attempt and generating an error. Set to zero for infinity. |
30 |
| Internal Command Timeout |
The time to wait (in seconds) while trying to execute a an internal command before terminating the attempt and generating an error. -1 uses CommandTimeout, 0 means no timeout. |
-1 |
| Keepalive |
The number of seconds of connection inactivity before Npgsql sends a keepalive query. |
disabled |
| Tcp Keepalive |
Whether to use TCP keepalive with system defaults if overrides isn't specified. |
disabled |
| Tcp Keepalive Time |
The number of milliseconds of connection inactivity before a TCP keepalive query is sent. Use of this option is discouraged, use KeepAlive instead if possible. Supported only on Windows. |
disabled |
| Tcp Keepalive Interval |
The interval, in milliseconds, between when successive keep-alive packets are sent if no acknowledgement is received. TcpKeepAliveTime must be non-zero as well. Supported only on Windows. |
value of TcpKeepAliveTime |
| Parameter |
Description |
Default |
| Max Auto Prepare |
The maximum number SQL statements that can be automatically prepared at any given point. Beyond this number the least-recently-used statement will be recycled. Zero disables automatic preparation. |
0 |
| Auto Prepare Min Usages |
The minimum number of usages an SQL statement is used before it's automatically prepared. |
5 |
| Use Perf Counters |
Makes Npgsql write performance information about connection use to Windows Performance Counters. Read the docs for more info. |
|
| Read Buffer Size |
Determines the size of the internal buffer Npgsql uses when reading. Increasing may improve performance if transferring large values from the database. |
8192 |
| Write Buffer Size |
Determines the size of the internal buffer Npgsql uses when writing. Increasing may improve performance if transferring large values to the database. |
8192 |
| Socket Receive Buffer Size |
Determines the size of socket receive buffer. |
System-dependent |
| Socket Send Buffer Size |
Determines the size of socket send buffer. |
System-dependent |
| No Reset On Close |
Improves performance in some cases by not resetting the connection state when it is returned to the pool, at the cost of leaking state. Use only if benchmarking shows a performance improvement |
false |
Misc
| Parameter |
Description |
Default |
| Application Name |
The optional application name parameter to be sent to the backend during connection initiation. |
|
| Enlist |
Whether to enlist in an ambient TransactionScope. |
true |
| Search Path |
Sets the schema search path. |
|
| Client Encoding |
Gets or sets the client_encoding parameter. Since 3.1. |
|
| Timezone |
Gets or sets the session timezone, PGTZ environment variable can be used instead. Since 3.3. |
|
| EF Template Database |
The database template to specify when creating a database in Entity Framework. |
template1 |
| Load Table Composites |
Load table composite type definitions, and not just free-standing composite types. |
false |
Compatibility
| Parameter |
Description |
Default |
| Server Compatibility Mode |
A compatibility mode for special PostgreSQL server types. Currently "Redshift" is supported, as well as "NoTypeLoading", which will bypass the normal type loading mechanism from the PostgreSQL catalog tables and supports a hardcoded list of basic types . |
none |
| Convert Infinity DateTime |
Makes MaxValue and MinValue timestamps and dates readable as infinity and negative infinity. |
false |