Command Line

pgloader loads data from various sources into PostgreSQL. It can transform the data it reads on the fly and submit raw SQL before and after the loading. It uses the COPY PostgreSQL protocol to stream the data into the server, and manages errors by filling a pair of reject.dat and reject.log files.

pgloader operates either using commands which are read from files:

pgloader commands.load

or by using arguments and options all provided on the command line:



The pgloader arguments can be as many load files as needed, or a couple of connection strings to a specific input file.

Source Connection String

The source connection string format is as follows:


Where format might be one of csv, fixed, copy, dbf, db3 or ixf.:


Where db might be of sqlite, mysql or mssql.

When using a file based source format, pgloader also support natively fetching the file from an http location and decompressing an archive if needed. In that case it’s necessary to use the –type option to specify the expected format of the file. See the examples below.

Also note that some file formats require describing some implementation details such as columns to be read and delimiters and quoting when loading from csv.

For more complex loading scenarios, you will need to write a full fledge load command in the syntax described later in this document.

Target Connection String

The target connection string format is described in details later in this document, see Section Connection String.


Inquiry Options

Use these options when you want to know more about how to use pgloader, as those options will cause pgloader not to load any data.


Show command usage summary and exit.


Show pgloader version string and exit.


List known encodings in this version of pgloader.


Parse given files in the command line as pgloader.conf files with the INI syntax that was in use in pgloader versions 2.x, and output the new command syntax for pgloader on standard output.

General Options

Those options are meant to tweak pgloader behavior when loading data.


Be verbose.


Be quiet.


Show debug level information messages.


Set the root working directory (defaults to /tmp/pgloader).


Set the pgloader log file (defaults to /tmp/pgloader/pgloader.log).


Minimum level of verbosity needed for log message to make it to the logfile. One of critical, log, error, warning, notice, info or debug.


Minimum level of verbosity needed for log message to make it to the console. One of critical, log, error, warning, notice, info or debug.


A filename where to copy the summary output. When relative, the filename is expanded into *root-dir*.

The format of the filename defaults to being human readable. It is

possible to have the output in machine friendly formats such as CSV, COPY (PostgreSQL’s own COPY format) or JSON by specifying a filename with the extension resp. .csv, .copy or .json.

--load-lisp-file <file>

Specify a lisp <file> to compile and load into the pgloader image before reading the commands, allowing to define extra transformation function. Those functions should be defined in the pgloader.transforms package. This option can appear more than once in the command line.


Allow testing a .load file without actually trying to load any data. It’s useful to debug it until it’s ok, in particular to fix connection strings.


Alter pgloader behavior: rather than trying to be smart about error handling and continue loading good data, separating away the bad one, just stop as soon as PostgreSQL refuses anything sent to it. Useful to debug data processing, transformation function and specific type casting.

--self-upgrade <directory>

Specify a <directory> where to find pgloader sources so that one of the very first things it does is dynamically loading-in (and compiling to machine code) another version of itself, usually a newer one like a very recent git checkout.


Uses the OpenSSL option to accept a locally issued server-side certificate, avoiding the following error message:


The right way to fix the SSL issue is to use a trusted certificate, of course. Sometimes though it’s useful to make progress with the pgloader setup while the certificate chain of trust is being fixed, maybe by another team. That’s when this option is useful.

Command Line Only Operations

Those options are meant to be used when using pgloader from the command line only, rather than using a command file and the rich command clauses and parser. In simple cases, it can be much easier to use the SOURCE and TARGET directly on the command line, then tweak the loading with those options:

--with <option>

Allows setting options from the command line. You can use that option as many times as you want. The option arguments must follow the WITH clause for the source type of the SOURCE specification, as described later in this document.


Allows setting PostgreSQL configuration from the command line. Note that the option parsing is the same as when used from the SET command clause, in particular you must enclose the guc value with single-quotes.

Use --set "guc_name='value'".


Allows setting a source field definition. Fields are accumulated in the order given on the command line. It’s possible to either use a --field option per field in the source file, or to separate field definitions by a comma, as you would do in the HAVING FIELDS clause.

--cast <rule>

Allows setting a specific casting rule for loading the data.

--type <csv|fixed|db3|ixf|sqlite|mysql|mssql>

Allows forcing the source type, in case when the SOURCE parsing isn’t satisfying.

--encoding <encoding>

Set the encoding of the source file to load data from.

--before <filename>

Parse given filename for SQL queries and run them against the target database before loading the data from the source. The queries are parsed by pgloader itself: they need to be terminated by a semi-colon (;) and the file may include i or ir commands to include another file.

--after <filename>

Parse given filename for SQL queries and run them against the target database after having loaded the data from the source. The queries are parsed in the same way as with the –before option, see above.

More Debug Information

To get the maximum amount of debug information, you can use both the –verbose and the –debug switches at the same time, which is equivalent to saying –client-min-messages data. Then the log messages will show the data being processed, in the cases where the code has explicit support for it.