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pgloader.1
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.\" generated with Ronn/v0.7.3
.\" http://github.com/rtomayko/ronn/tree/0.7.3
.
.TH "PGLOADER" "1" "November 2017" "ff" ""
.
.SH "NAME"
\fBpgloader\fR \- PostgreSQL data loader
.
.SH "SYNOPSIS"
.
.nf
pgloader [<options>] [<command\-file>]\.\.\.
pgloader [<options>] SOURCE TARGET
.
.fi
.
.SH "DESCRIPTION"
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 \fBCOPY\fR PostgreSQL protocol to stream the data into the server, and manages errors by filling a pair of \fIreject\.dat\fR and \fIreject\.log\fR files\.
.
.P
pgloader operates either using commands which are read from files:
.
.IP "" 4
.
.nf
pgloader commands\.load
.
.fi
.
.IP "" 0
.
.P
or by using arguments and options all provided on the command line:
.
.IP "" 4
.
.nf
pgloader SOURCE TARGET
.
.fi
.
.IP "" 0
.
.SH "ARGUMENTS"
The pgloader arguments can be as many load files as needed, or a couple of connection strings to a specific input file\.
.
.SS "SOURCE CONNECTION STRING"
The source connection string format is as follows:
.
.IP "" 4
.
.nf
format:///absolute/path/to/file\.ext
format://\./relative/path/to/file\.ext
.
.fi
.
.IP "" 0
.
.P
Where format might be one of \fBcsv\fR, \fBfixed\fR, \fBcopy\fR, \fBdbf\fR, \fBdb3\fR or \fBixf\fR\.
.
.IP "" 4
.
.nf
db://user:pass@host:port/dbname
.
.fi
.
.IP "" 0
.
.P
Where db might be of \fBsqlite\fR, \fBmysql\fR or \fBmssql\fR\.
.
.P
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 \fB\-\-type\fR option to specify the expected format of the file\. See the examples below\.
.
.P
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\.
.
.P
For more complex loading scenarios, you will need to write a full fledge load command in the syntax described later in this document\.
.
.SS "TARGET CONNECTION STRING"
The target connection string format is described in details later in this document, see Section Connection String\.
.
.SH "OPTIONS"
.
.SS "INQUIRY OPTIONS"
Use these options when you want to know more about how to use \fBpgloader\fR, as those options will cause \fBpgloader\fR not to load any data\.
.
.TP
\fB\-h\fR, \fB\-\-help\fR
Show command usage summary and exit\.
.
.TP
\fB\-V\fR, \fB\-\-version\fR
Show pgloader version string and exit\.
.
.TP
\fB\-E\fR, \fB\-\-list\-encodings\fR
List known encodings in this version of pgloader\.
.
.TP
\fB\-U\fR, \fB\-\-upgrade\-config\fR
Parse given files in the command line as \fBpgloader\.conf\fR files with the \fBINI\fR syntax that was in use in pgloader versions 2\.x, and output the new command syntax for pgloader on standard output\.
.
.SS "GENERAL OPTIONS"
Those options are meant to tweak \fBpgloader\fR behavior when loading data\.
.
.IP "\(bu" 4
\fB\-v\fR, \fB\-\-verbose\fR: Be verbose\.
.
.IP "\(bu" 4
\fB\-q\fR, \fB\-\-quiet\fR: Be quiet\.
.
.IP "\(bu" 4
\fB\-d\fR, \fB\-\-debug\fR: Show debug level information messages\.
.
.IP "\(bu" 4
\fB\-D\fR, \fB\-\-root\-dir\fR: Set the root working directory (default to "/tmp/pgloader")\.
.
.IP "\(bu" 4
\fB\-L\fR, \fB\-\-logfile\fR: Set the pgloader log file (default to "/tmp/pgloader\.log")\.
.
.IP "\(bu" 4
\fB\-\-log\-min\-messages\fR: Minimum level of verbosity needed for log message to make it to the logfile\. One of critical, log, error, warning, notice, info or debug\.
.
.IP "\(bu" 4
\fB\-\-client\-min\-messages\fR: Minimum level of verbosity needed for log message to make it to the console\. One of critical, log, error, warning, notice, info or debug\.
.
.IP "\(bu" 4
\fB\-S\fR, \fB\-\-summary\fR: A filename where to copy the summary output\. When relative, the filename is expanded into \fB*root\-dir*\fR\.
.
.IP
The format of the filename defaults to being \fIhuman readable\fR\. It is possible to have the output in machine friendly formats such as \fICSV\fR, \fICOPY\fR (PostgreSQL\'s own COPY format) or \fIJSON\fR by specifying a filename with the extension resp\. \fB\.csv\fR, \fB\.copy\fR or \fB\.json\fR\.
.
.IP "\(bu" 4
\fB\-l <file>\fR, \fB\-\-load\-lisp\-file <file>\fR: Specify a lisp \fIfile\fR 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 \fBpgloader\.transforms\fR package\. This option can appear more than once in the command line\.
.
.IP "\(bu" 4
\fB\-\-dry\-run\fR:
.
.IP
Allow testing a \fB\.load\fR file without actually trying to load any data\. It\'s useful to debug it until it\'s ok, in particular to fix connection strings\.
.
.IP "\(bu" 4
\fB\-\-on\-error\-stop\fR
.
.IP
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\.
.
.IP "\(bu" 4
\fB\-\-self\-upgrade <directory>\fR:
.
.IP
Specify a \fIdirectory\fR 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\.
.
.IP "" 0
.
.SS "COMMAND LINE ONLY OPERATIONS"
Those options are meant to be used when using \fBpgloader\fR 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 \fISOURCE\fR and \fITARGET\fR directly on the command line, then tweak the loading with those options:
.
.IP "\(bu" 4
\fB\-\-with "option"\fR:
.
.IP
Allows setting options from the command line\. You can use that option as many times as you want\. The option arguments must follow the \fIWITH\fR clause for the source type of the \fBSOURCE\fR specification, as described later in this document\.
.
.IP "\(bu" 4
\fB\-\-set "guc_name=\'value\'"\fR
.
.IP
Allows setting PostgreSQL configuration from the command line\. Note that the option parsing is the same as when used from the \fISET\fR command clause, in particular you must enclose the guc value with single\-quotes\.
.
.IP "\(bu" 4
\fB\-\-field "\.\.\."\fR
.
.IP
Allows setting a source field definition\. Fields are accumulated in the order given on the command line\. It\'s possible to either use a \fB\-\-field\fR option per field in the source file, or to separate field definitions by a comma, as you would do in the \fIHAVING FIELDS\fR clause\.
.
.IP "\(bu" 4
\fB\-\-cast "\.\.\."\fR
.
.IP
Allows setting a specific casting rule for loading the data\.
.
.IP "\(bu" 4
\fB\-\-type csv|fixed|db3|ixf|sqlite|mysql|mssql\fR
.
.IP
Allows forcing the source type, in case when the \fISOURCE\fR parsing isn\'t satisfying\.
.
.IP "\(bu" 4
\fB\-\-encoding <encoding>\fR
.
.IP
Set the encoding of the source file to load data from\.
.
.IP "\(bu" 4
\fB\-\-before <filename>\fR
.
.IP
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 \fB\ei\fR or \fB\eir\fR commands to \fIinclude\fR another file\.
.
.IP "\(bu" 4
\fB\-\-after <filename>\fR
.
.IP
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 \fB\-\-before\fR option, see above\.
.
.IP "" 0
.
.SS "MORE DEBUG INFORMATION"
To get the maximum amount of debug information, you can use both the \fB\-\-verbose\fR and the \fB\-\-debug\fR switches at the same time, which is equivalent to saying \fB\-\-client\-min\-messages data\fR\. Then the log messages will show the data being processed, in the cases where the code has explicit support for it\.
.
.SH "USAGE EXAMPLES"
Review the command line options and pgloader\'s version:
.
.IP "" 4
.
.nf
pgloader \-\-help
pgloader \-\-version
.
.fi
.
.IP "" 0
.
.SS "Loading from a complex command"
Use the command file as the pgloader command argument, pgloader will parse that file and execute the commands found in it:
.
.IP "" 4
.
.nf
pgloader \-\-verbose \./test/csv\-districts\.load
.
.fi
.
.IP "" 0
.
.SS "CSV"
Load data from a CSV file into a pre\-existing table in your database, having pgloader guess the CSV properties (separator, quote and escape character):
.
.IP "" 4
.
.nf
pgloader \./test/data/matching\-1\.csv pgsql:///pgloader?tablename=matching
.
.fi
.
.IP "" 0
.
.P
Load data from a CSV file into a pre\-existing table in your database, with expanded options:
.
.IP "" 4
.
.nf
pgloader \-\-type csv \e
\-\-field id \-\-field field \e
\-\-with truncate \e
\-\-with "fields terminated by \',\'" \e
\./test/data/matching\-1\.csv \e
postgres:///pgloader?tablename=matching
.
.fi
.
.IP "" 0
.
.P
In that example the whole loading is driven from the command line, bypassing the need for writing a command in the pgloader command syntax entirely\. As there\'s no command though, the extra inforamtion needed must be provided on the command line using the \fB\-\-type\fR and \fB\-\-field\fR and \fB\-\-with\fR switches\.
.
.P
For documentation about the available syntaxes for the \fB\-\-field\fR and \fB\-\-with\fR switches, please refer to the CSV section later in the man page\.
.
.P
Note also that the PostgreSQL URI includes the target \fItablename\fR\.
.
.SS "Reading from STDIN"
File based pgloader sources can be loaded from the standard input, as in the following example:
.
.IP "" 4
.
.nf
pgloader \-\-type csv \e
\-\-field "usps,geoid,aland,awater,aland_sqmi,awater_sqmi,intptlat,intptlong" \e
\-\-with "skip header = 1" \e
\-\-with "fields terminated by \'\et\'" \e
\- \e
postgresql:///pgloader?districts_longlat \e
< test/data/2013_Gaz_113CDs_national\.txt
.
.fi
.
.IP "" 0
.
.P
The dash (\fB\-\fR) character as a source is used to mean \fIstandard input\fR, as usual in Unix command lines\. It\'s possible to stream compressed content to pgloader with this technique, using the Unix pipe:
.
.IP "" 4
.
.nf
gunzip \-c source\.gz | pgloader \-\-type csv \.\.\. \- pgsql:///target?foo
.
.fi
.
.IP "" 0
.
.SS "Loading from CSV available through HTTP"
The same command as just above can also be run if the CSV file happens to be found on a remote HTTP location:
.
.IP "" 4
.
.nf
pgloader \-\-type csv \e
\-\-field "usps,geoid,aland,awater,aland_sqmi,awater_sqmi,intptlat,intptlong" \e
\-\-with "skip header = 1" \e
\-\-with "fields terminated by \'\et\'" \e
http://pgsql\.tapoueh\.org/temp/2013_Gaz_113CDs_national\.txt \e
postgresql:///pgloader?districts_longlat
.
.fi
.
.IP "" 0
.
.P
Some more options have to be used in that case, as the file contains a one\-line header (most commonly that\'s column names, could be a copyright notice)\. Also, in that case, we specify all the fields right into a single \fB\-\-field\fR option argument\.
.
.P
Again, the PostgreSQL target connection string must contain the \fItablename\fR option and you have to ensure that the target table exists and may fit the data\. Here\'s the SQL command used in that example in case you want to try it yourself:
.
.IP "" 4
.
.nf
create table districts_longlat
(
usps text,
geoid text,
aland bigint,
awater bigint,
aland_sqmi double precision,
awater_sqmi double precision,
intptlat double precision,
intptlong double precision
);
.
.fi
.
.IP "" 0
.
.P
Also notice that the same command will work against an archived version of the same data, e\.g\. http://pgsql\.tapoueh\.org/temp/2013_Gaz_113CDs_national\.txt\.gz\.
.
.P
Finally, it\'s important to note that pgloader first fetches the content from the HTTP URL it to a local file, then expand the archive when it\'s recognized to be one, and only then processes the locally expanded file\.
.
.P
In some cases, either because pgloader has no direct support for your archive format or maybe because expanding the archive is not feasible in your environment, you might want to \fIstream\fR the content straight from its remote location into PostgreSQL\. Here\'s how to do that, using the old battle tested Unix Pipes trick:
.
.IP "" 4
.
.nf
curl http://pgsql\.tapoueh\.org/temp/2013_Gaz_113CDs_national\.txt\.gz \e
| gunzip \-c \e
| pgloader \-\-type csv \e
\-\-field "usps,geoid,aland,awater,aland_sqmi,awater_sqmi,intptlat,intptlong"
\-\-with "skip header = 1" \e
\-\-with "fields terminated by \'\et\'" \e
\- \e
postgresql:///pgloader?districts_longlat
.
.fi
.
.IP "" 0
.
.P
Now the OS will take care of the streaming and buffering between the network and the commands and pgloader will take care of streaming the data down to PostgreSQL\.
.
.SS "Migrating from SQLite"
The following command will open the SQLite database, discover its tables definitions including indexes and foreign keys, migrate those definitions while \fIcasting\fR the data type specifications to their PostgreSQL equivalent and then migrate the data over:
.
.IP "" 4
.
.nf
createdb newdb
pgloader \./test/sqlite/sqlite\.db postgresql:///newdb
.
.fi
.
.IP "" 0
.
.SS "Migrating from MySQL"
Just create a database where to host the MySQL data and definitions and have pgloader do the migration for you in a single command line:
.
.IP "" 4
.
.nf
createdb pagila
pgloader mysql://user@localhost/sakila postgresql:///pagila
.
.fi
.
.IP "" 0
.
.SS "Fetching an archived DBF file from a HTTP remote location"
It\'s possible for pgloader to download a file from HTTP, unarchive it, and only then open it to discover the schema then load the data:
.
.IP "" 4
.
.nf
createdb foo
pgloader \-\-type dbf http://www\.insee\.fr/fr/methodes/nomenclatures/cog/telechargement/2013/dbf/historiq2013\.zip postgresql:///foo
.
.fi
.
.IP "" 0
.
.P
Here it\'s not possible for pgloader to guess the kind of data source it\'s being given, so it\'s necessary to use the \fB\-\-type\fR command line switch\.
.
.SH "BATCHES AND RETRY BEHAVIOUR"
To load data to PostgreSQL, pgloader uses the \fBCOPY\fR streaming protocol\. While this is the faster way to load data, \fBCOPY\fR has an important drawback: as soon as PostgreSQL emits an error with any bit of data sent to it, whatever the problem is, the whole data set is rejected by PostgreSQL\.
.
.P
To work around that, pgloader cuts the data into \fIbatches\fR of 25000 rows each, so that when a problem occurs it\'s only impacting that many rows of data\. Each batch is kept in memory while the \fBCOPY\fR streaming happens, in order to be able to handle errors should some happen\.
.
.P
When PostgreSQL rejects the whole batch, pgloader logs the error message then isolates the bad row(s) from the accepted ones by retrying the batched rows in smaller batches\. To do that, pgloader parses the \fICONTEXT\fR error message from the failed COPY, as the message contains the line number where the error was found in the batch, as in the following example:
.
.IP "" 4
.
.nf
CONTEXT: COPY errors, line 3, column b: "2006\-13\-11"
.
.fi
.
.IP "" 0
.
.P
Using that information, pgloader will reload all rows in the batch before the erroneous one, log the erroneous one as rejected, then try loading the remaining of the batch in a single attempt, which may or may not contain other erroneous data\.
.
.P
At the end of a load containing rejected rows, you will find two files in the \fIroot\-dir\fR location, under a directory named the same as the target database of your setup\. The filenames are the target table, and their extensions are \fB\.dat\fR for the rejected data and \fB\.log\fR for the file containing the full PostgreSQL client side logs about the rejected data\.
.
.P
The \fB\.dat\fR file is formatted in PostgreSQL the text COPY format as documented in http://www\.postgresql\.org/docs/9\.2/static/sql\-copy\.html#AEN66609 \fI\fR\.
.
.SH "A NOTE ABOUT PERFORMANCE"
pgloader has been developed with performance in mind, to be able to cope with ever growing needs in loading large amounts of data into PostgreSQL\.
.
.P
The basic architecture it uses is the old Unix pipe model, where a thread is responsible for loading the data (reading a CSV file, querying MySQL, etc) and fills pre\-processed data into a queue\. Another threads feeds from the queue, apply some more \fItransformations\fR to the input data and stream the end result to PostgreSQL using the COPY protocol\.
.
.P
When given a file that the PostgreSQL \fBCOPY\fR command knows how to parse, and if the file contains no erroneous data, then pgloader will never be as fast as just using the PostgreSQL \fBCOPY\fR command\.
.
.P
Note that while the \fBCOPY\fR command is restricted to read either from its standard input or from a local file on the server\'s file system, the command line tool \fBpsql\fR implements a \fB\ecopy\fR command that knows how to stream a file local to the client over the network and into the PostgreSQL server, using the same protocol as pgloader uses\.
.
.SH "A NOTE ABOUT PARALLELISM"
pgloader uses several concurrent tasks to process the data being loaded:
.
.IP "\(bu" 4
a reader task reads the data in and pushes it to a queue,
.
.IP "\(bu" 4
at last one write task feeds from the queue and formats the raw into the PostgreSQL COPY format in batches (so that it\'s possible to then retry a failed batch without reading the data from source again), and then sends the data to PostgreSQL using the COPY protocol\.
.
.IP "" 0
.
.P
The parameter \fIworkers\fR allows to control how many worker threads are allowed to be active at any time (that\'s the parallelism level); and the parameter \fIconcurrency\fR allows to control how many tasks are started to handle the data (they may not all run at the same time, depending on the \fIworkers\fR setting)\.
.
.P
We allow \fIworkers\fR simultaneous workers to be active at the same time in the context of a single table\. A single unit of work consist of several kinds of workers:
.
.IP "\(bu" 4
a reader getting raw data from the source,
.
.IP "\(bu" 4
N writers preparing and sending the data down to PostgreSQL\.
.
.IP "" 0
.
.P
The N here is setup to the \fIconcurrency\fR parameter: with a \fICONCURRENCY\fR of 2, we start (+ 1 2) = 3 concurrent tasks, with a \fIconcurrency\fR of 4 we start (+ 1 4) = 9 concurrent tasks, of which only \fIworkers\fR may be active simultaneously\.
.
.P
The defaults are \fBworkers = 4, concurrency = 1\fR when loading from a database source, and \fBworkers = 8, concurrency = 2\fR when loading from something else (currently, a file)\. Those defaults are arbitrary and waiting for feedback from users, so please consider providing feedback if you play with the settings\.
.
.P
As the \fBCREATE INDEX\fR threads started by pgloader are only waiting until PostgreSQL is done with the real work, those threads are \fINOT\fR counted into the concurrency levels as detailed here\.
.
.P
By default, as many \fBCREATE INDEX\fR threads as the maximum number of indexes per table are found in your source schema\. It is possible to set the \fBmax parallel create index\fR \fIWITH\fR option to another number in case there\'s just too many of them to create\.
.
.SH "SOURCE FORMATS"
pgloader supports the following input formats:
.
.IP "\(bu" 4
csv, which includes also tsv and other common variants where you can change the \fIseparator\fR and the \fIquoting\fR rules and how to \fIescape\fR the \fIquotes\fR themselves;
.
.IP "\(bu" 4
fixed columns file, where pgloader is flexible enough to accomodate with source files missing columns (\fIragged fixed length column files\fR do exist);
.
.IP "\(bu" 4
PostgreSLQ COPY formatted files, following the COPY TEXT documentation of PostgreSQL, such as the reject files prepared by pgloader;
.
.IP "\(bu" 4
dbase files known as db3 or dbf file;
.
.IP "\(bu" 4
ixf formated files, ixf being a binary storage format from IBM;
.
.IP "\(bu" 4
sqlite databases with fully automated discovery of the schema and advanced cast rules;
.
.IP "\(bu" 4
mysql databases with fully automated discovery of the schema and advanced cast rules;
.
.IP "\(bu" 4
MS SQL databases with fully automated discovery of the schema and advanced cast rules\.
.
.IP "" 0
.
.SH "PGLOADER COMMANDS SYNTAX"
pgloader implements a Domain Specific Language allowing to setup complex data loading scripts handling computed columns and on\-the\-fly sanitization of the input data\. For more complex data loading scenarios, you will be required to learn that DSL\'s syntax\. It\'s meant to look familiar to DBA by being inspired by SQL where it makes sense, which is not that much after all\.
.
.P
The pgloader commands follow the same global grammar rules\. Each of them might support only a subset of the general options and provide specific options\.
.
.IP "" 4
.
.nf
LOAD <source\-type>
FROM <source\-url>
[ HAVING FIELDS <source\-level\-options> ]
INTO <postgresql\-url>
[ TARGET TABLE [ "<schema>" ]\."<table name>" ]
[ TARGET COLUMNS <columns\-and\-options> ]
[ WITH <load\-options> ]
[ SET <postgresql\-settings> ]
[ BEFORE LOAD [ DO <sql statements> | EXECUTE <sql file> ] \.\.\. ]
[ AFTER LOAD [ DO <sql statements> | EXECUTE <sql file> ] \.\.\. ]
;
.
.fi
.
.IP "" 0
.
.P
The main clauses are the \fBLOAD\fR, \fBFROM\fR, \fBINTO\fR and \fBWITH\fR clauses that each command implements\. Some command then implement the \fBSET\fR command, or some specific clauses such as the \fBCAST\fR clause\.
.
.SH "TEMPLATING WITH MUSTACHE"
pgloader implements the https://mustache\.github\.io/ templating system so that you may have dynamic parts of your commands\. See the documentation for this template system online\.
.
.P
A specific feature of pgloader is the ability to fetch a variable from the OS environment of the pgloader process, making it possible to run pgloader as in the following example:
.
.IP "" 4
.
.nf
$ DBPATH=sqlite/sqlite\.db pgloader \./test/sqlite\-env\.load
.
.fi
.
.IP "" 0
.
.P
or in several steps:
.
.IP "" 4
.
.nf
$ export DBPATH=sqlite/sqlite\.db
$ pgloader \./test/sqlite\-env\.load
.
.fi
.
.IP "" 0
.
.P
The variable can then be used in a typical mustache fashion:
.
.IP "" 4
.
.nf
load database
from \'{{DBPATH}}\'
into postgresql:///pgloader;
.
.fi
.
.IP "" 0
.
.P
It\'s also possible to prepare a INI file such as the following:
.
.IP "" 4
.
.nf
[pgloader]
DBPATH = sqlite/sqlite\.db
.
.fi
.
.IP "" 0
.
.P
And run the following command, feeding the INI values as a \fIcontext\fR for pgloader templating system:
.
.IP "" 4
.
.nf
$ pgloader \-\-context \./test/sqlite\.ini \./test/sqlite\-ini\.load
.
.fi
.
.IP "" 0
.
.P
The mustache templates implementation with OS environment support replaces former \fBGETENV\fR implementation, which didn\'t work anyway\.
.
.SH "COMMON CLAUSES"
Some clauses are common to all commands:
.
.IP "\(bu" 4
\fIFROM\fR
.
.IP
The \fIFROM\fR clause specifies where to read the data from, and each command introduces its own variant of sources\. For instance, the \fICSV\fR source supports \fBinline\fR, \fBstdin\fR, a filename, a quoted filename, and a \fIFILENAME MATCHING\fR clause (see above); whereas the \fIMySQL\fR source only supports a MySQL database URI specification\.
.
.IP "\(bu" 4
\fIINTO\fR
.
.IP
The PostgreSQL connection URI must contains the name of the target table where to load the data into\. That table must have already been created in PostgreSQL, and the name might be schema qualified\.
.
.IP
Then \fIINTO\fR option also supports an optional comma separated list of target columns, which are either the name of an input \fIfield\fR or the white space separated list of the target column name, its PostgreSQL data type and a \fIUSING\fR expression\.
.
.IP
The \fIUSING\fR expression can be any valid Common Lisp form and will be read with the current package set to \fBpgloader\.transforms\fR, so that you can use functions defined in that package, such as functions loaded dynamically with the \fB\-\-load\fR command line parameter\.
.
.IP
Each \fIUSING\fR expression is compiled at runtime to native code\.
.
.IP
This feature allows pgloader to load any number of fields in a CSV file into a possibly different number of columns in the database, using custom code for that projection\.
.
.IP "\(bu" 4
\fIWITH\fR
.
.IP
Set of options to apply to the command, using a global syntax of either:
.
.IP "\(bu" 4
\fIkey = value\fR
.
.IP "\(bu" 4
\fIuse option\fR
.
.IP "\(bu" 4
\fIdo not use option\fR
.
.IP "" 0
.
.IP
See each specific command for details\.
.
.IP
All data sources specific commands support the following options:
.
.IP "\(bu" 4
\fIon error stop\fR
.
.IP "\(bu" 4
\fIbatch rows = R\fR
.
.IP "\(bu" 4
\fIbatch size = \.\.\. MB\fR
.
.IP "\(bu" 4
\fIprefetch rows = \.\.\.\fR
.
.IP "" 0
.
.IP
See the section BATCH BEHAVIOUR OPTIONS for more details\.
.
.IP
In addition, the following settings are available:
.
.IP "\(bu" 4
\fIworkers = W\fR
.
.IP "\(bu" 4
\fIconcurrency = C\fR
.
.IP "\(bu" 4
\fImax parallel create index = I\fR
.
.IP "" 0
.
.IP
See section A NOTE ABOUT PARALLELISM for more details\.
.
.IP "\(bu" 4
\fISET\fR
.
.IP
This clause allows to specify session parameters to be set for all the sessions opened by pgloader\. It expects a list of parameter name, the equal sign, then the single\-quoted value as a comma separated list\.
.
.IP
The names and values of the parameters are not validated by pgloader, they are given as\-is to PostgreSQL\.
.
.IP "\(bu" 4
\fIBEFORE LOAD DO\fR
.
.IP
You can run SQL queries against the database before loading the data from the \fBCSV\fR file\. Most common SQL queries are \fBCREATE TABLE IF NOT EXISTS\fR so that the data can be loaded\.
.
.IP
Each command must be \fIdollar\-quoted\fR: it must begin and end with a double dollar sign, \fB$$\fR\. Dollar\-quoted queries are then comma separated\. No extra punctuation is expected after the last SQL query\.
.
.IP "\(bu" 4
\fIBEFORE LOAD EXECUTE\fR
.
.IP
Same behaviour as in the \fIBEFORE LOAD DO\fR clause\. Allows you to read the SQL queries from a SQL file\. Implements support for PostgreSQL dollar\-quoting and the \fB\ei\fR and \fB\eir\fR include facilities as in \fBpsql\fR batch mode (where they are the same thing)\.
.
.IP "\(bu" 4
\fIAFTER LOAD DO\fR
.
.IP
Same format as \fIBEFORE LOAD DO\fR, the dollar\-quoted queries found in that section are executed once the load is done\. That\'s the right time to create indexes and constraints, or re\-enable triggers\.
.
.IP "\(bu" 4
\fIAFTER LOAD EXECUTE\fR
.
.IP
Same behaviour as in the \fIAFTER LOAD DO\fR clause\. Allows you to read the SQL queries from a SQL file\. Implements support for PostgreSQL dollar\-quoting and the \fB\ei\fR and \fB\eir\fR include facilities as in \fBpsql\fR batch mode (where they are the same thing)\.
.
.IP "" 0
.
.SS "Connection String"
The \fB<postgresql\-url>\fR parameter is expected to be given as a \fIConnection URI\fR as documented in the PostgreSQL documentation at http://www\.postgresql\.org/docs/9\.3/static/libpq\-connect\.html#LIBPQ\-CONNSTRING\.
.
.IP "" 4
.
.nf
postgresql://[user[:password]@][netloc][:port][/dbname][?option=value&\.\.\.]
.
.fi
.
.IP "" 0
.
.P
Where:
.
.IP "\(bu" 4
\fIuser\fR
.
.IP
Can contain any character, including colon (\fB:\fR) which must then be doubled (\fB::\fR) and at\-sign (\fB@\fR) which must then be doubled (\fB@@\fR)\.
.
.IP
When omitted, the \fIuser\fR name defaults to the value of the \fBPGUSER\fR environment variable, and if it is unset, the value of the \fBUSER\fR environment variable\.
.
.IP "\(bu" 4
\fIpassword\fR
.
.IP
Can contain any character, including the at sign (\fB@\fR) which must then be doubled (\fB@@\fR)\. To leave the password empty, when the \fIuser\fR name ends with at at sign, you then have to use the syntax user:@\.
.
.IP
When omitted, the \fIpassword\fR defaults to the value of the \fBPGPASSWORD\fR environment variable if it is set, otherwise the password is left unset\.
.
.IP
When no \fIpassword\fR is found either in the connection URI nor in the environment, then pgloader looks for a \fB\.pgpass\fR file as documented at https://www\.postgresql\.org/docs/current/static/libpq\-pgpass\.html\. The implementation is not that of \fBlibpq\fR though\. As with \fBlibpq\fR you can set the environment variable \fBPGPASSFILE\fR to point to a \fB\.pgpass\fR file, and pgloader defaults to \fB~/\.pgpass\fR on unix like systems and \fB%APPDATA%\epostgresql\epgpass\.conf\fR on windows\. Matching rules and syntax are the same as with \fBlibpq\fR, refer to its documentation\.
.
.IP "\(bu" 4
\fInetloc\fR
.
.IP
Can be either a hostname in dotted notation, or an ipv4, or an Unix domain socket path\. Empty is the default network location, under a system providing \fIunix domain socket\fR that method is preferred, otherwise the \fInetloc\fR default to \fBlocalhost\fR\.
.
.IP
It\'s possible to force the \fIunix domain socket\fR path by using the syntax \fBunix:/path/to/where/the/socket/file/is\fR, so to force a non default socket path and a non default port, you would have:
.
.IP "" 4
.
.nf
postgresql://unix:/tmp:54321/dbname
.
.fi
.
.IP "" 0
.
.IP
The \fInetloc\fR defaults to the value of the \fBPGHOST\fR environment variable, and if it is unset, to either the default \fBunix\fR socket path when running on a Unix system, and \fBlocalhost\fR otherwise\.
.
.IP
Socket path containing colons are supported by doubling the colons within the path, as in the following example:
.
.IP "" 4
.
.nf
postgresql://unix:/tmp/project::region::instance:5432/dbname
.
.fi
.
.IP "" 0
.
.IP "\(bu" 4
\fIdbname\fR
.
.IP
Should be a proper identifier (letter followed by a mix of letters, digits and the punctuation signs comma (\fB,\fR), dash (\fB\-\fR) and underscore (\fB_\fR)\.
.
.IP
When omitted, the \fIdbname\fR defaults to the value of the environment variable \fBPGDATABASE\fR, and if that is unset, to the \fIuser\fR value as determined above\.
.
.IP "\(bu" 4
\fIoptions\fR
.
.IP
The optional parameters must be supplied with the form \fBname=value\fR, and you may use several parameters by separating them away using an ampersand (\fB&\fR) character\.
.
.IP
Only some options are supported here, \fItablename\fR (which might be qualified with a schema name) \fIsslmode\fR, \fIhost\fR, \fIport\fR, \fIdbname\fR, \fIuser\fR and \fIpassword\fR\.
.
.IP
The \fIsslmode\fR parameter values can be one of \fBdisable\fR, \fBallow\fR, \fBprefer\fR or \fBrequire\fR\.
.
.IP
For backward compatibility reasons, it\'s possible to specify the \fItablename\fR option directly, without spelling out the \fBtablename=\fR parts\.
.
.IP
The options override the main URI components when both are given, and using the percent\-encoded option parameters allow using passwords starting with a colon and bypassing other URI components parsing limitations\.
.
.IP "" 0
.
.SS "Regular Expressions"
Several clauses listed in the following accept \fIregular expressions\fR with the following input rules:
.
.IP "\(bu" 4
A regular expression begins with a tilde sign (\fB~\fR),
.
.IP "\(bu" 4
is then followed with an opening sign,
.
.IP "\(bu" 4
then any character is allowed and considered part of the regular expression, except for the closing sign,
.
.IP "\(bu" 4
then a closing sign is expected\.
.
.IP "" 0
.
.P
The opening and closing sign are allowed by pair, here\'s the complete list of allowed delimiters:
.
.IP "" 4
.
.nf
~//
~[]
~{}
~()
~<>
~""
~\'\'
~||
~##
.
.fi
.
.IP "" 0
.
.P
Pick the set of delimiters that don\'t collide with the \fIregular expression\fR you\'re trying to input\. If your expression is such that none of the solutions allow you to enter it, the places where such expressions are allowed should allow for a list of expressions\.
.
.SS "Comments"
Any command may contain comments, following those input rules:
.
.IP "\(bu" 4
the \fB\-\-\fR delimiter begins a comment that ends with the end of the current line,
.
.IP "\(bu" 4
the delimiters \fB/*\fR and \fB*/\fR respectively start and end a comment, which can be found in the middle of a command or span several lines\.
.
.IP "" 0
.
.P
Any place where you could enter a \fIwhitespace\fR will accept a comment too\.
.
.SS "Batch behaviour options"
All pgloader commands have support for a \fIWITH\fR clause that allows for specifying options\. Some options are generic and accepted by all commands, such as the \fIbatch behaviour options\fR, and some options are specific to a data source kind, such as the CSV \fIskip header\fR option\.
.
.P
The global batch behaviour options are:
.
.IP "\(bu" 4
\fIbatch rows\fR
.
.IP
Takes a numeric value as argument, used as the maximum number of rows allowed in a batch\. The default is \fB25 000\fR and can be changed to try having better performance characteristics or to control pgloader memory usage;
.
.IP "\(bu" 4
\fIbatch size\fR
.
.IP
Takes a memory unit as argument, such as \fI20 MB\fR, its default value\. Accepted multipliers are \fIkB\fR, \fIMB\fR, \fIGB\fR, \fITB\fR and \fIPB\fR\. The case is important so as not to be confused about bits versus bytes, we\'re only talking bytes here\.
.
.IP "\(bu" 4
\fIprefetch rows\fR
.
.IP
Takes a numeric value as argument, defaults to \fB100000\fR\. That\'s the number of rows that pgloader is allowed to read in memory in each reader thread\. See the \fIworkers\fR setting for how many reader threads are allowed to run at the same time\.
.
.IP "" 0
.
.P
Other options are specific to each input source, please refer to specific parts of the documentation for their listing and covering\.
.
.P
A batch is then closed as soon as either the \fIbatch rows\fR or the \fIbatch size\fR threshold is crossed, whichever comes first\. In cases when a batch has to be closed because of the \fIbatch size\fR setting, a \fIdebug\fR level log message is printed with how many rows did fit in the \fIoversized\fR batch\.
.
.SH "LOAD CSV"
This command instructs pgloader to load data from a \fBCSV\fR file\. Here\'s an example:
.
.IP "" 4
.
.nf
LOAD CSV
FROM \'GeoLiteCity\-Blocks\.csv\' WITH ENCODING iso\-646\-us
HAVING FIELDS
(
startIpNum, endIpNum, locId
)
INTO postgresql://user@localhost:54393/dbname
TARGET TABLE geolite\.blocks
TARGET COLUMNS
(
iprange ip4r using (ip\-range startIpNum endIpNum),
locId
)
WITH truncate,
skip header = 2,
fields optionally enclosed by \'"\',
fields escaped by backslash\-quote,
fields terminated by \'\et\'
SET work_mem to \'32 MB\', maintenance_work_mem to \'64 MB\';
.
.fi
.
.IP "" 0
.
.P
The \fBcsv\fR format command accepts the following clauses and options:
.
.IP "\(bu" 4
\fIFROM\fR