Juttle PostgreSQL Adapter
PostgreSQL adapter for the Juttle data flow language, with read & write support.
Examples
Read rows from your logs SQL table where the log level is info, with the
read postgres -table 'logs' level = 'info'Perform an equivalent query using the -raw option:
read postgres -raw 'select * from "logs" where "level" = "info" limit 10000'Add a debug option to return the final SQL query instead (before any pagination):
read postgres -table "logs" -debug true level = "info"will output: {query: 'select * from "logs" where "level" = 'info' limit 10000'}.
If you have time series data in your table, indicate the column with the
timestamp using the timeField option to paginate and sort data correctly:
read postgres -timeField "create_time" -table "logs";read postgres -timeField "create_time" -table "logs -from :2 days ago: -to :1 hour ago:;"The content of the column indicated by timeField will appear as the time
field in resulting points.
An end-to-end example is described here and deployed to the demo system demo.juttle.io.
Installation
Like Juttle itself, the adapter is installed as a npm package. Both Juttle and the adapter need to be installed side-by-side:
$ npm install juttle$ npm install juttle-postgres-adapterConfiguration
The adapter needs to be registered and configured so that it can be used from
within Juttle. To do so, use the following format when adding a Postgres configuration to your ~/.juttle/config.json file:
Read options
| Name | Type | Required | Description |
|---|---|---|---|
table |
string | yes | table to query |
raw |
string | no | send a raw SQL query to PostgreSQL |
debug |
boolean | no | output a query corresponding to current set of options and filters |
timeField |
string | no | assume date time column, to and from options will use this to limit rows by time. Include this option to sort results by time. |
fetchSize |
integer | no | row limit, defaults to 10000 records |
from |
moment | no | select points after this time (inclusive) |
to |
moment | no | select points before this time (exclusive) |
db |
string | no | select the database name to use in your instance |
id |
string | no | select the config instance to use |
Write options
| Name | Type | Required | Description |
|---|---|---|---|
table |
string | yes | table to write points into |
db |
string | no | select the database name to use in your instance |
id |
string | no | select the config instance to use |
Numeric Types
When reading numeric data types of variable storage size
from PostgreSQL, values are treated as type String in juttle.
You may want to use Number.fromString() function
in the juttle program if your data has numbers of these types.
When juttle reads fields of PostgreSQL real and double precision types, their values are treated as numbers.
Time Zones
Use the timestamp with time zone date type in your postgres table to avoid time zone confusion. If your timestamp value does not have a time zone, Postgres will use the local system TimeZone parameter and then convert to UTC.
Contributing
Contributions are welcome! Please file an issue or open a pull request.
To check code style and run unit tests:
npm test
Both are run automatically by Travis.