--- title: PostgreSQL slug: litmusedge/product-features/integration/integration-connectors/sql/postgresql description: Review parameters for the PostgreSQL connector. docTags: createdAt: 2026-10-15T16:17:16.760Z --- The PostgreSQL connector writes Litmus Edge (LE) DeviceHub messages into a table in a PostgreSQL database. The connector writes rows in batches, and uses one transaction for each batch. The connector also supports Execute Command for ad-hoc SQL queries. ## Supported communication - Outbound (write data from LE to the database): Yes - Inbound (read data from the database to LE): No - Execute Command (ad-hoc SQL query): Yes ## Compatibility The following product and version are validated. Other products and versions might work. | Product | Version | | ---------- | ------- | | PostgreSQL | 12 | ## Connector configuration | Field | Type | Description | Required | Default | | ---------------------- | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------- | --------- | | Name | String | Name of this connector instance. | Yes | `-` | | Hostname | String | DNS name or IP address of the PostgreSQL host. The host must be reachable from the LE system. Length is `3` to `255` characters. | Yes | `-` | | Port | Integer | Port of the PostgreSQL host. Range is `1` to `65535`. | Yes | `5432` | | SSL Mode | Dropdown | TLS connection mode: `disable`, `require`, `verify-ca`, or `verify-full`. | No | `disable` | | CA Certificate | String (Secret) | CA certificate for TLS. You can also add it to the system-wide certificate list. Applies only when **SSL Mode** is not `disable`. | No | `-` | | Certificate | String (Secret) | PEM client certificate for mutual TLS authentication. Applies only when **SSL Mode** is not `disable`. | No | `-` | | Private key | String (Secret) | Private key that matches the client certificate. Applies only when **SSL Mode** is not `disable`. | No | `-` | | Username | String | Database user that the connector authenticates as. | Yes | `-` | | Password | String (Secret) | Password for the database user. Not needed for trust or certificate authentication. | No | `-` | | Database | String | Name of the target database. | Yes | `-` | | Schema | String | Schema that holds the target table. Leave it empty to use the database's default search path, which is usually `public`. | No | `-` | | Table | String | Target table that the connector writes into. The table must exist unless you enable **Create table**. | Yes | `-` | | Mapping | Object | Key-value pairs that map payload data to the columns of your table. The key is a column in your table. The value is a payload field name such as `deviceId`, the matching default-schema column name such as `device_id`, or static text with an `@` prefix, such as `@plant-a`. Leave it empty to use the default table schema. | No | `-` | | Enable JSONPath | Boolean | Read **Mapping** values that start with `$` as JSONPath expressions, such as `$.factory.line.machine.sensors.temperature`. Values that don't start with `$` keep their usual meaning, and an expression that matches nothing writes `NULL`. | No | Disabled | | Create table | Boolean | Create the target table with the default table schema if it doesn't exist. The database user needs permission to create a table. | Yes | Disabled | | Commit timeout | Integer | Maximum time in milliseconds that one batch insert transaction can take before the connector treats it as failed and retries it. Range is `10` to `65535`. | No | `30000` | | Batch timeout | Integer | Maximum time in milliseconds after the previous commit attempt before the connector writes a batch that isn't full. Range is `10` to `65535`. | No | `500` | | Max transaction size | Integer | Maximum number of messages in one batch insert. The connector writes a full batch without waiting for **Batch timeout**. Range is `1` to `65535`. | No | `500` | | Bulk insert count | Integer | Number of messages the connector buffers before it writes a batch. A value of `0` uses **Max transaction size**. Range is `0` to `65535`. | No | `0` | | Write mode | Dropdown | When a message counts as delivered: `sync` or `async`. | No | `sync` | | Parallel transactions | Integer | Maximum number of batch inserts that run at the same time, each on its own database connection. Values above `1` increase throughput, but the connector can then write rows out of publish order. Range is `1` to `64`. | No | `1` | | Parallel Publish Count | Integer | Number of messages the connector publishes at the same time. In `sync` write mode, this value limits how many rows a batch can collect. Range is `1` to `4000`. | No | `1000` | ## Additional attributes | Field | Type | Description | Required | Default | | ----------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------- | -------- | | Throttling limit | Integer | Maximum outbound messages per second. A value of `0` disables throttling. Minimum is `0`. | No | `0` | | Persistent storage | Boolean | Store outbound queue messages on disk. If the connection drops or the system loses power, the messages are retained and sent once the connection is restored. | No | Enabled | | Persistent storage size limit | Integer | Maximum disk space in GB used for persisted data. Applies only when **Persistent storage** is enabled. Minimum is `1`. | Conditional | `1` | | Queue Mode | Dropdown | Order in which the connector sends buffered messages. `fifo` sends the earliest message first. `lifo` sends the latest message first. Applies only when **Persistent storage** is enabled. | No | `lifo` | | Enable Logging | Boolean | Write connection and publish error messages to the connector log. Logging can increase CPU usage, so enable it only for debugging. | No | Disabled | ## SSL modes | Value | Behavior | | ------------- | ----------------------------------------------------------------------------------------- | | `disable` | No TLS. | | `require` | The connector encrypts the connection but doesn't verify the server certificate. | | `verify-ca` | The connector verifies the server certificate against the CA certificate. | | `verify-full` | The connector verifies the CA certificate and the host name. Use this mode in production. | ## Default table schema When you enable **Create table** and the target table doesn't exist, the connector creates it with the following schema. ```sql CREATE TABLE IF NOT EXISTS TABLE_NAME ( id BIGSERIAL NOT NULL, record_uuid UUID NOT NULL, arrived_at TIMESTAMP WITH TIME ZONE NOT NULL, device_id VARCHAR(64) NULL, register_id VARCHAR(64) NULL, tag_name VARCHAR(64) NULL, datatype VARCHAR(32) NULL, value VARCHAR NULL, success BOOLEAN NULL, PRIMARY KEY (id) ); ``` To write into a table with different columns, create the table yourself and use **Mapping**. For mapping and JSONPath examples, see the integration guide. ## Write modes | Write mode | Behavior | | ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `sync` | The connector acknowledges a message only after it commits the batch that holds the message. If the database is unreachable, the message stays in persistent storage, and the connector writes it after it reconnects. | | `async` | The connector acknowledges a message once it buffers it. If a batch fails to write, the connector drops it and counts the messages as dropped. | :::hint{type="warning"} **Caution:** In `async` write mode, or with **Persistent storage** disabled, you can lose data during a database outage. Use `async` only when throughput matters more than delivery. ::: ## IT Hub Use the [IT Hub Processor](docId\:d34bVo1TMgjw01Ga7K3yj) to run an ad-hoc SQL query through the connector. The connector streams the result back one message per row, on the response topic supplied in the request. ## Related topics - [Add a Connector](docId:4YVfCEP7GYScJHMKYFCuM) - [Manage Connectors](docId\:tQoP7QtquSQqDq9yhbJ34) - [IT Hub Processor](docId\:d34bVo1TMgjw01Ga7K3yj)