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pgloader/pgloader.1.md
Dimitri Fontaine de4ff30acc Implement --summary to copy the output to a file, fix #68. 
Given than redirecting a tty such as *terminal-io* isn't easy enough,
let's provide a way to copy the summary output to a file. Another way to
solve it would have been to output the summary to the main logs, but
that could have made the logs parsing more difficult that necessary.

Let's see how users like it...
2014-06-14 23:31:11 +02:00

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# pgloader(1) -- PostgreSQL data loader
## SYNOPSIS
`pgloader` [<options>] [<command-file>]...
## DESCRIPTION
pgloader loads data from different sources into PostgreSQL. It can tranform
the data it reads on the fly and send 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 fo *reject.dat* and *reject.log* files.
pgloader operates from commands which are read from files:
pgloader commands.load
## OPTIONS
* `-h`, `--help`:
Show command usage summary and exit.
* `-V`, `--version`:
Show pgloader version string and exit.
* `-v`, `--verbose`:
Be verbose.
* `-q`, `--quiet:
Be quiet.
* `-d`, `--debug`:
Show debug level information messages.
* `-D`, `--root-dir`:
Set the root working directory (default to "/tmp/pgloader").
* `-L`, `--logfile`:
Set the pgloader log file (default to "/tmp/pgloader.log").
* `--log-min-messages`:
Minimum level of verbosity needed for log message to make it to the
logfile. One of critical, log, error, warning, notice, info or debug.
* `--client-min-messages`:
Minimum level of verbosity needed for log message to make it to the
console. One of critical, log, error, warning, notice, info or debug.
* `-S`, `--summary`:
A filename where to copy the summary output. When relative, the filename
is expanded into `*root-dir`.
* `-E`, `--list-encodings`:
List known encodings in this version of pgloader.
* `-U`, `--upgrade-config`:
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.
* -l <file>, --load <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.
* --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.
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.
## BATCHES AND RETRY BEHAVIOUR
To load data to PostgreSQL, pgloader uses the `COPY` streaming protocol.
While this is the faster way to load data, `COPY` 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.
To work around that, pgloader cuts the data into *batches* 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 `COPY` streaming happens, in
order to be able to handle errors should some happen.
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 *CONTEXT* 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:
CONTEXT: COPY errors, line 3, column b: "2006-13-11"
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.
At the end of a load containing rejected rows, you will find two files in
the *root-dir* location, under a directory named the same as the target
database of your setup. The filenames are the target table, and their
extensions are `.dat` for the rejected data and `.log` for the file
containing the full PostgreSQL client side logs about the rejected data.
The `.dat` file is formated in PostgreSQL the text COPY format as documented
in [http://www.postgresql.org/docs/9.2/static/sql-copy.html#AEN66609]().
## A NOTE ABOUT PERFORMANCES
pgloader has been developped with performances in mind, to be able to cope
with ever growing needs in loading large amounts of data into PostgreSQL.
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 *transformations* to the input data and stream the
end result to PostgreSQL using the COPY protocol.
When given a file that the PostgreSQL `COPY` 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 `COPY` command.
Note that while the `COPY` 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 `psql` implements a `\copy` 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.
## COMMANDS
pgloader support the following commands:
- `LOAD CSV`
- `LOAD FIXED`
- `LOAD DBF`
- `LOAD SQLite`
- `LOAD MYSQL`
- `LOAD ARCHIVE`
- `LOAD DATABASE`
- `LOAD MESSAGES`
The pgloader commands follow the same grammar rules. Each of them might
support only a subset of the general options and provide specific options.
LOAD <something>
FROM <source-url> [ WITH <source-options> ]
INTO <postgresql-url>
[ WITH <load-options> ]
[ SET <postgresql-settings> ]
;
The main clauses are the `LOAD`, `FROM`, `INTO` and `WITH` clauses that each
command implements. Some command then implement the `SET` command, or some
specific clauses such as the `CAST` clause.
## COMMON CLAUSES
Some clauses are common to all commands:
- *INTO*
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.
Then *INTO* option also supports an optional comma separated list of
target columns, which are either the name of an input *field* or the
whitespace separated list of the target column name, its PostgreSQL data
type and a *USING* expression.
The *USING* expression can be any valid Common Lisp form and will be
read with the current package set to `pgloader.transforms`, so that you
can use functions defined in that package, such as functions loaded
dynamically with the `--load` command line parameter.
Each *USING* expression is compiled at runtime to native code.
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.
- *WITH*
Set of options to apply to the command, using a global syntax of either:
- *key = value*
- *use option*
- *do not use option*
See each specific command for details.
- *SET*
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.
The names and values of the parameters are not validated by pgloader,
they are given as-is to PostgreSQL.
- *BEFORE LOAD DO*
You can run SQL queries against the database before loading the data
from the `CSV` file. Most common SQL queries are `CREATE TABLE IF NOT
EXISTS` so that the data can be loaded.
Each command must be *dollar-quoted*: it must begin and end with a
double dollar sign, `$$`. Dollar-quoted queries are then comma
separated. No extra punctuation is expected after the last SQL query.
- *BEFORE LOAD EXECUTE*
Same behaviour as in the *BEFORE LOAD DO* clause. Allows you to read
the SQL queries from a SQL file. Implements support for PostgreSQL
dollar-quoting and the `\i` and `\ir` include facilities as in `psql`
batch mode (where they are the same thing).
- *AFTER LOAD DO*
Same format as *BEFORE LOAD DO*, 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.
- *AFTER LOAD EXECUTE*
Same behaviour as in the *AFTER LOAD DO* clause. Allows you to read the
SQL queries from a SQL file. Implements support for PostgreSQL
dollar-quoting and the `\i` and `\ir` include facilities as in `psql`
batch mode (where they are the same thing).
### Connection String
The `<source-url>` parameter is expected to be given as a *Connection URI*
as documented in the PostgreSQL documentation at
http://www.postgresql.org/docs/9.3/static/libpq-connect.html#LIBPQ-CONNSTRING.
postgresql://[user[:password]@][netloc][:port][/dbname][?schema.table]
Where:
- *user*
Can contain any character, including colon (`:`) which must then be
doubled (`::`) and at-sign (`@`) which must then be doubled (`@@`).
When ommited, the *user* name defaults to the value of the `PGUSER`
environment variable, and if it is unset, the value of the `USER`
environment variable.
- *password*
Can contain any character, including that at sign (`@`) which must then
be doubled (`@@`). To leave the password empty, when the *user* name
ends with at at sign, you then have to use the syntax user:@.
When ommited, the *password* defaults to the value of the `PGPASSWORD`
environement variable if it is set, otherwise the password is left
unset.
- *netloc*
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 *unix domain socket* that method is prefered, otherwise
the *netloc* default to `localhost`.
It's possible to force the *unix domain socket* path by using the syntax
`unix:/path/to/where/the/socket/file/is`, so to force a non default
socket path and a non default port, you would have:
postgresql://unix:/tmp:54321/dbname
The *netloc* defaults to the value of the `PGHOST` environement
variable, and if it is unset, to either the default `unix` socket path
when running on a Unix system, and `localhost` otherwise.
- *dbname*
Should be a proper identifier (letter followed by a mix of letters,
digits and the punctuation signs comma (`,`), dash (`-`) and underscore
(`_`).
When ommited, the *dbname* defaults to the value of the environment
variable `PGDATABASE`, and if that is unset, to the *user* value as
determined above.
- The only optionnal parameter should be a possibly qualified table name.
### Regular Expressions
Several clauses listed in the following accept *regular expressions* with
the following input rules:
- A regular expression begins with a tilde sign (`~`),
- is then followed with an opening sign,
- then any character is allowed and considered part of the regular
expression, except for the closing sign,
- then a closing sign is expected.
The opening and closing sign are allowed by pair, here's the complete list
of allowed delimiters:
~//
~[]
~{}
~()
~<>
~""
~''
~||
~##
Pick the set of delimiters that don't collide with the *regular expression*
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.
### Comments
Any command may contain comments, following those input rules:
- the `--` delimiter begins a comment that ends with the end of the
current line,
- the delimiters `/*` and `*/` respectively start and end a comment, which
can be found in the middle of a command or span several lines.
Any place where you could enter a *whitespace* will accept a comment too.
### Batch behaviour options
All pgloader commands have support for a *WITH* clause that allows for
specifying options. Some options are generic and accepted by all commands,
such as the *batch behaviour options*, and some options are specific to a
data source kind, such as the CSV *skip header* options.
The global batch behaviour options are:
- *batch rows*
Takes a numeric value as argument, used as the maximum number of rows
allowed in a batch. The default is `25 000` and can be changed to try
having better performances characteristics or to control pgloader memory
usage;
- *batch size*
Takes a memory unit as argument, such as *20 MB*, its default value.
Accepted multipliers are *kB*, *MB*, *GB*, *TB* and *PB*. The case is
important so as not to be confused about bits versus bytes, we're only
talking bytes here.
- *batch concurrency*
Takes a numeric value as argument, defaults to `10`. That's the number
of batches that pgloader is allows to build in memory, even when only a
single batch at a time might be sent to PostgreSQL.
Supporting more than a single batch being sent at a time is on the TODO
list of pgloader, but is not implemented yet. This option is about
controling the memory needs of pgloader as a trade-off to the
performances characteristics, and not about parallel activity of
pgloader.
Other options are specific to each input source, please refer to specific
parts of the documentation for their listing and covering.
## LOAD CSV
This command instructs pgloader to load data from a `CSV` file. Here's an
example:
LOAD CSV
FROM 'GeoLiteCity-Blocks.csv' WITH ENCODING iso-646-us
HAVING FIELDS
(
startIpNum, endIpNum, locId
)
INTO postgresql://user@localhost:54393/dbname?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 '\t'
SET work_mem to '32 MB', maintenance_work_mem to '64 MB';
The `csv` format command accepts the following clauses and options:
- *FROM*
Filename where to load the data from. Accepts an *ENCODING* option. Use
the `--list-encodings` option to know which encoding names are
supported.
The filename may be enclosed by single quotes, and could be one of the
following special values:
- *inline*
The data is found after the end of the parsed commands. Any number
of empty lines between the end of the commands and the beginning of
the data is accepted.
- *stdin*
Reads the data from the standard input stream.
- *FILENAMES MATCHING*
The whole *matching* clause must follow the following rule:
[ ALL FILENAMES | [ FIRST ] FILENAME ]
MATCHING regexp
[ IN DIRECTORY '...' ]
The *matching* clause applies given *regular expression* (see above
for exact syntax, several options can be used here) to filenames.
It's then possible to load data from only the first match of all of
them.
The optional *IN DIRECTORY* clause allows specifying which directory
to walk for finding the data files, and can be either relative to
where the command file is read from, or absolute. The given
directory must exists.
The *FROM* option also supports an optional comma separated list of
*field* names describing what is expected in the `CSV` data file,
optionally introduced by the clause `HAVING FIELDS`.
Each field name can be either only one name or a name following with
specific reader options for that field. Supported per-field reader
options are:
- *terminated by*
See the description of *field terminated by* below.
The processing of this option is not currently implemented.
- *date format*
When the field is expected of the date type, then this option allows
to specify the date format used in the file.
The processing of this option is not currently implemented.
- *null if*
This option takes an argument which is either the keyword *blanks*
or a double-quoted string.
When *blanks* is used and the field value that is read contains only
space characters, then it's automatically converted to an SQL `NULL`
value.
When a double-quoted string is used and that string is read as the
field value, then the field value is automatically converted to an
SQL `NULL` value.
- *WITH*
When loading from a `CSV` file, the following options are supported:
- *truncate*
When this option is listed, pgloader issues a `TRUNCATE` command
against the PostgreSQL target table before reading the data file.
- *skip header*
Takes a numeric value as argument. Instruct pgloader to skip that
many lines at the beginning of the input file.
- *trim unquoted blanks*
When reading unquoted values in the `CSV` file, remove the blanks
found in between the separator and the value. That behaviour is the
default.
- *keep unquoted blanks*
When reading unquoted values in the `CSV` file, keep blanks found in
between the separator and the value.
- *fields optionally enclosed by*
Takes a single character as argument, which must be found inside
single quotes, and might be given as the printable character itself,
the special value \t to denote a tabulation character, or `0x` then
an hexadecimal value read as the ascii code for the character.
This character is used as the quoting character in the `CSV` file,
and defaults to double-quote.
- *fields not enclosed*
By default, pgloader will use the double-quote character as the
enclosing character. If you have a CSV file where fields are not
enclosed and are using double-quote as an expected ordinary
character, then use the option *fields not enclosed* for the CSV
parser to accept those values.
- *fields escaped by*
Takes either the special value *backslash-quote* or *double-quote*.
This value is used to recognize escaped field separators when they
are to be found within the data fields themselves. Defaults to
*double-quote*.
- *fields terminated by*
Takes a single character as argument, which must be found inside
single quotes, and might be given as the printable character itself,
the special value \t to denote a tabulation character, or `0x` then
an hexadecimal value read as the ascii code for the character.
This character is used as the *field separator* when reading the
`CSV` data.
- *lines terminated by*
Takes a single character as argument, which must be found inside
single quotes, and might be given as the printable character itself,
the special value \t to denote a tabulation character, or `0x` then
an hexadecimal value read as the ascii code for the character.
This character is used to recognize *end-of-line* condition when
reading the `CSV` data.
## LOAD FIXED COLS
This command instructs pgloader to load data from a text file containing
columns arranged in a *fixed size* manner. Here's an example:
LOAD FIXED
FROM inline (a 0 10, b 10 8, c 18 8, d 26 17)
INTO postgresql:///pgloader?fixed
(
a, b,
c time using (time-with-no-separator c),
d
)
WITH truncate
SET client_encoding to 'latin1',
work_mem to '14MB',
standard_conforming_strings to 'on'
BEFORE LOAD DO
$$ drop table if exists fixed; $$,
$$ create table fixed (
a integer,
b date,
c time,
d text
);
$$;
01234567892008052011431250firstline
01234562008052115182300left blank-padded
12345678902008052208231560another line
The `fixed` format command accepts the following clauses and options:
- *FROM*
Filename where to load the data from. Accepts an *ENCODING* option. Use
the `--list-encodings` option to know which encoding names are
supported.
The filename may be enclosed by single quotes, and could be one of the
following special values:
- *inline*
The data is found after the end of the parsed commands. Any number
of empty lines between the end of the commands and the beginning of
the data is accepted.
- *stdin*
Reads the data from the standard input stream.
The *FROM* option also supports an optional comma separated list of
*field* names describing what is expected in the `FIXED` data file.
Each field name is composed of the field name followed with specific
reader options for that field. Supported per-field reader options are
the following, where only *start* and *length* are required.
- *start*
Position in the line where to start reading that field's value. Can
be entered with decimal digits or `0x` then hexadecimal digits.
- *length*
How many bytes to read from the *start* position to read that
field's value. Same format as *start*.
- *terminated by*
See the description of *field terminated by* below.
The processing of this option is not currently implemented.
- *date format*
When the field is expected of the date type, then this option allows
to specify the date format used in the file.
The processing of this option is not currently implemented.
- *null if*
This option takes an argument which is either the keyword *blanks*
or a double-quoted string.
When *blanks* is used and the field value that is read contains only
space characters, then it's automatically converted to an SQL `NULL`
value.
When a double-quoted string is used and that string is read as the
field value, then the field value is automatically converted to an
SQL `NULL` value.
- *WITH*
When loading from a `CSV` file, the following options are supported:
- *truncate*
When this option is listed, pgloader issues a `TRUNCATE` command
against the PostgreSQL target table before reading the data file.
- *skip header*
Takes a numeric value as argument. Instruct pgloader to skip that
many lines at the beginning of the input file.
## LOAD DBF
This command instructs pgloader to load data from a `DBF` file. Here's an
example:
LOAD DBF
FROM http://www.insee.fr/fr/methodes/nomenclatures/cog/telechargement/2013/dbf/reg2013.dbf
INTO postgresql://user@localhost/dbname
WITH truncate, create table;
The `dbf` format command accepts the following clauses and options:
- *FROM*
Filename where to load the data from. This support local files, HTTP
URLs and zip files containing a single dbf file of the same name. Fetch
such a zip file from an HTTP address is of course supported.
- *WITH*
When loading from a `DBF` file, the following options are supported:
- *truncate*
When this option is listed, pgloader issues a `TRUNCATE` command
against the PostgreSQL target table before reading the data file.
- *create table*
When this option is listed, pgloader creates the table using the
meta data found in the `DBF` file, which must contain a list of
fields with their data type. A standard data type conversion from
DBF to PostgreSQL is done.
- *table name*
This options expects as its value the possibly qualified name of the
table to create.
## LOAD ARCHIVE
This command instructs pgloader to load data from one or more files contained
in an archive. Currently the only supported archive format is *ZIP*, and the
archive might be downloaded from an *HTTP* URL.
Here's an example:
LOAD ARCHIVE
FROM /Users/dim/Downloads/GeoLiteCity-latest.zip
INTO postgresql:///ip4r
BEFORE LOAD DO
$$ create extension if not exists ip4r; $$,
$$ create schema if not exists geolite; $$,
$$ create table if not exists geolite.location
(
locid integer primary key,
country text,
region text,
city text,
postalcode text,
location point,
metrocode text,
areacode text
);
$$,
$$ create table if not exists geolite.blocks
(
iprange ip4r,
locid integer
);
$$,
$$ drop index if exists geolite.blocks_ip4r_idx; $$,
$$ truncate table geolite.blocks, geolite.location cascade; $$
LOAD CSV
FROM FILENAME MATCHING ~/GeoLiteCity-Location.csv/
WITH ENCODING iso-8859-1
(
locId,
country,
region null if blanks,
city null if blanks,
postalCode null if blanks,
latitude,
longitude,
metroCode null if blanks,
areaCode null if blanks
)
INTO postgresql:///ip4r?geolite.location
(
locid,country,region,city,postalCode,
location point using (format nil "(~a,~a)" longitude latitude),
metroCode,areaCode
)
WITH skip header = 2,
fields optionally enclosed by '"',
fields escaped by double-quote,
fields terminated by ','
AND LOAD CSV
FROM FILENAME MATCHING ~/GeoLiteCity-Blocks.csv/
WITH ENCODING iso-8859-1
(
startIpNum, endIpNum, locId
)
INTO postgresql:///ip4r?geolite.blocks
(
iprange ip4r using (ip-range startIpNum endIpNum),
locId
)
WITH skip header = 2,
fields optionally enclosed by '"',
fields escaped by double-quote,
fields terminated by ','
FINALLY DO
$$ create index blocks_ip4r_idx on geolite.blocks using gist(iprange); $$;
The `archive` command accepts the following clauses and options:
- *FROM*
Filename or HTTP URI where to load the data from. When given an HTTP
URL the linked file will get downloaded locally before processing.
If the file is a `zip` file, the command line utility `unzip` is used
to expand the archive into files in `$TMPDIR`, or `/tmp` if `$TMPDIR`
is unset or set to a non-existing directory.
Then the following commands are used from the top level directory where
the archive has been expanded.
- command [ *AND* command ... ]
A series of commands against the contents of the archive, at the moment
only `CSV`,`'FIXED` and `DBF` commands are supported.
Note that commands are supporting the clause *FROM FILENAME MATCHING*
which allows the pgloader command not to depend on the exact names of
the archive directories.
The same clause can also be applied to several files with using the
spelling *FROM ALL FILENAMES MATCHING* and a regular expression.
The whole *matching* clause must follow the following rule:
FROM [ ALL FILENAMES | [ FIRST ] FILENAME ] MATCHING
- *FINALLY DO*
SQL Queries to run once the data is loaded, such as `CREATE INDEX`.
## LOAD MYSQL DATABASE
This command instructs pgloader to load data from a database connection. The
only supported database source is currently *MySQL*, and pgloader supports
dynamically converting the schema of the source database and the indexes
building.
A default set of casting rules are provided and might be overloaded and
appended to by the command.
Here's an example:
LOAD DATABASE
FROM mysql://root@localhost/sakila
INTO postgresql://localhost:54393/sakila
WITH include drop, create tables, create indexes, reset sequences
SET maintenance_work_mem to '128MB',
work_mem to '12MB',
search_path to 'sakila'
CAST type datetime to timestamptz drop default drop not null using zero-dates-to-null,
type date drop not null drop default using zero-dates-to-null,
-- type tinyint to boolean using tinyint-to-boolean,
type year to integer
MATERIALIZE VIEWS film_list, staff_list
-- INCLUDING ONLY TABLE NAMES MATCHING ~/film/, 'actor'
-- EXCLUDING TABLE NAMES MATCHING ~<ory>
-- DECODING TABLE NAMES MATCHING ~/messed/, ~/encoding/ AS utf8
BEFORE LOAD DO
$$ create schema if not exists sakila; $$;
The `database` command accepts the following clauses and options:
- *FROM*
Must be a connection URL pointing to a MySQL database. At the moment
only MySQL is supported as a pgloader source.
If the connection URI contains a table name, then only this table is
migrated from MySQL to PostgreSQL.
- *WITH*
When loading from a `MySQL` database, the following options are
supported:
- *include drop*
When this option is listed, pgloader drop in the PostgreSQL
connection all the table whose names have been found in the MySQL
database. This option allows for using the same command several
times in a row until you figure out all the options, starting
automatically from a clean environment.
- *include no drop*
When this option is listed, pgloader will not include any `DROP`
statement when loading the data.
- *truncate*
When this option is listed, pgloader issue the `TRUNCATE` command
against each PostgreSQL table just before loading data into it.
- *no truncate*
When this topion is listed, pgloader issues no `TRUNCATE` command.
- *create tables*
When this option is listed, pgloader creates the table using the
meta data found in the `MySQL` file, which must contain a list of
fields with their data type. A standard data type conversion from
DBF to PostgreSQL is done.
- *create no tables*
When this option is listed, pgloader skips the creation of table
before lading data, target tables must then already exist.
- *create indexes*
When this option is listed, pgloader gets the definitions of all the
indexes found in the MySQL database and create the same set of index
definitions against the PostgreSQL database.
- *create no indexes*
When this option is listed, pgloader skips the creating indexes.
- *foreign keys*
When this option is listed, pgloader gets the definitions of all the
foreign keys found in the MySQL database and create the same set of
foreign key definitions against the PostgreSQL database.
- *no foreign keys*
When this option is listed, pgloader skips creating foreign keys.
- *reset sequences*
When this option is listed, at the end of the data loading and after
the indexes have all been created, pgloader resets all the
PostgreSQL sequences created to the current maximum value of the
column they are attached to.
The options *schema only* and *data only* have no effects on this
option.
- *reset no sequences*
When this option is listed, pgloader skips resetting sequences after
the load.
The options *schema only* and *data only* have no effects on this
option.
- *downcase identifiers*
When this option is listed, pgloader converts all MySQL identifiers
(table names, index names, column names) to *downcase*, except for
PostgreSQL *reserved* keywords.
The PostgreSQL *reserved* keywords are determined dynamically by
using the system function `pg_get_keywords()`.
- *quote identifiers*
When this option is listed, pgloader quotes all MySQL identifiers so
that their case is respected. Note that you will then have to do the
same thing in your application code queries.
- *schema only*
When this option is listed pgloader refrains from migrating the data
over. Note that the schema in this context includes the indexes when
the option *create indexes* has been listed.
- *data only*
When this option is listed pgloader only issues the `COPY`
statements, without doing any other processing.
- *CAST*
The cast clause allows to specify custom casting rules, either to
overload the default casting rules or to amend them with special cases.
A casting rule is expected to follow one of the forms:
type <mysql-type-name> [ <guard> ... ] to <pgsql-type-name> [ <option> ... ]
column <table-name>.<column-name> [ <guards> ] to ...
It's possible for a *casting rule* to either match against a MySQL data
type or against a given *column name* in a given *table name*. That
flexibility allows to cope with cases where the type `tinyint` might
have been used as a `boolean` in some cases but as a `smallint` in
others.
The *casting rules* are applied in order, the first match prevents
following rules to be applied, and user defined rules are evaluated
first.
The supported guards are:
- *when default 'value'*
The casting rule is only applied against MySQL columns of the source
type that have given *value*, which must be a single-quoted or a
double-quoted string.
- *when typemod expression*
The casting rule is only applied against MySQL columns of the source
type that have a *typemod* value matching the given *typemod
expression*. The *typemod* is separated into its *precision* and
*scale* components.
Example of a cast rule using a *typemod* guard:
type char when (= precision 1) to char keep typemod
This expression casts MySQL `char(1)` column to a PostgreSQL column
of type `char(1)` while allowing for the general case `char(N)` will
be converted by the default cast rule into a PostgreSQL type
`varchar(N)`.
The supported casting options are:
- *drop default*, *keep default*
When the option *drop default* is listed, pgloader drops any
existing default expression in the MySQL database for columns of the
source type from the `CREATE TABLE` statement it generates.
The spelling *keep default* explicitely prevents that behavior and
can be used to overlad the default casting rules.
- *drop not null*, *keep not null*
When the option *drop not null* is listed, pgloader drops any
existing `NOT NULL` constraint associated with the given source
MySQL datatype when it creates the tables in the PostgreSQL
database.
The spelling *keep not null* explicitely prevents that behavior and
can be used to overlad the default casting rules.
- *drop typemod*, *keep typemod*
When the option *drop typemod* is listed, pgloader drops any
existing *typemod* definition (e.g. *precision* and *scale*) from
the datatype definition found in the MySQL columns of the source
type when it created the tables in the PostgreSQL database.
The spelling *keep typemod* explicitely prevents that behavior and
can be used to overlad the default casting rules.
- *using*
This option takes as its single argument the name of a function to
be found un the `pgloader.transforms` Common Lisp package. See above
for details.
It's possible to augment a default cast rule (such as one that
applies against `ENUM` data type for example) with a *transformation
function* by omitting entirely the `type` parts of the casting rule,
as in the following example:
column enumerate.foo using empty-string-to-null
- *MATERIALIZE VIEWS*
This clause allows you to implement custom data processing at the data
source by providing a *view definition* against which pgloader will
query the data. It's not possible to just allow for plain `SQL` because
we want to know a lot about the exact data types of each column involved
in the query output.
This clause expect a comma separated list of view definitions, each one
being either the name of an existing view in your database or the
following expression:
*name* `AS` `$$` *sql query* `$$`
The *name* and the *sql query* will be used in a `CREATE VIEW` statement
at the beginning of the data loading, and the resulting view will then
be dropped at the end of the data loading.
- *MATERIALIZE ALL VIEWS*
Same behaviour as *MATERIALIZE VIEWS* using the dynamic list of views as
returned by MySQL rather than asking the user to specify the list.
- *INCLUDING ONLY TABLE NAMES MATCHING*
Introduce a comma separated list of table names or *regular expression*
used to limit the tables to migrate to a sublist.
Example:
INCLUDING ONLY TABLE NAMES MATCHING ~/film/, 'actor'
- *EXCLUDING TABLE NAMES MATCHING*
Introduce a comma separated list of table names or *regular expression*
used to exclude table names from the migration. This filter only applies
to the result of the *INCLUDING* filter.
EXCLUDING TABLE NAMES MATCHING ~<ory>
- *DECODING TABLE NAMES MATCHING*
Introduce a comma separated list of table names or *regular expressions*
used to force the encoding to use when processing data from MySQL. If
the data encoding known to you is different from MySQL's idea about it,
this is the option to use.
DECODING TABLE NAMES MATCHING ~/messed/, ~/encoding/ AS utf8
You can use as many such rules as you need, all with possibly different
encodings.
### LIMITATIONS
The `database` command currently only supports MySQL source database and has
the following limitations:
- Views are not migrated,
Supporting views might require implemeting a full SQL parser for the
MySQL dialect with a porting engine to rewrite the SQL against
PostgreSQL, including renaming functions and changing some constructs.
While it's not theorically impossible, don't hold your breath.
- Triggers are not migrated
The difficulty of doing so is not yet assessed.
- `ON UPDATE CURRENT_TIMESTAMP` is currently not migrated
It's simple enough to implement, just not on the priority list yet.
- Of the geometric datatypes, onle the `POINT` database has been covered.
The other ones should be easy enough to implement now, it's just not
done yet.
### DEFAULT MySQL CASTING RULES
When migrating from MySQL the following Casting Rules are provided:
Numbers:
- type int to serial when auto_increment and (< precision 10)
- type int to bigserial when auto_increment and (<= 10 precision)
- type int to int when not auto_increment and (< precision 10)
- type int to bigint when not auto_increment and (<= 10 precision)
- type smallint to serial when auto_increment
- type bigint to bigserial when auto_increment
- type tinyint to boolean when (= 1 precision) using tinyint-to-boolean
- type tinyint to smallint drop typemod
- type smallint to smallint drop typemod
- type mediumint to integer drop typemod
- type integer to integer drop typemod
- type float to float drop typemod
- type bigint to bigint drop typemod
- type double to double precision drop typemod
- type numeric to numeric keep typemod
- type decimal to deciman keep typemod
Texts:
- type char to varchar keep typemod
- type varchar to text
- type tinytext to text
- type text to text
- type mediumtext to text
- type longtext to text
Binary:
- type binary to bytea
- type varbinary to bytea
- type tinyblob to bytea
- type blob to bytea
- type mediumblob to bytea
- type longblob to bytea
Date:
- type datetime when default "0000-00-00 00:00:00" and not null
to timestamptz drop not null drop default
using zero-dates-to-null
- type datetime when default "0000-00-00 00:00:00"
to timestamptz drop default
using zero-dates-to-null
- type timestamp when default "0000-00-00 00:00:00" and not null
to timestamptz drop not null drop default
using zero-dates-to-null
- type timestamp when default "0000-00-00 00:00:00"
to timestamptz drop default
using zero-dates-to-null
- type date when default "0000-00-00" to date drop default
using zero-dates-to-null
- type date to date
- type datetime to timestamptz
- type timestamp to timestamptz
- type year to integer drop typemod
Geometric:
- type point to point using pgloader.transforms::convert-mysql-point
Enum types are declared inline in MySQL and separately with a `CREATE TYPE`
command in PostgreSQL, so each column of Enum Type is converted to a type
named after the table and column names defined with the same labels in the
same order.
When the source type definition is not matched in the default casting rules
nor in the casting rules provided in the command, then the type name with
the typemod is used.
## LOAD SQLite DATABASE
This command instructs pgloader to load data from a SQLite file. Automatic
discovery of the schema is supported, including build of the indexes.
Here's an example:
load database
from sqlite:///Users/dim/Downloads/lastfm_tags.db
into postgresql:///tags
with drop tables, create tables, create indexes, reset sequences
set work_mem to '16MB', maintenance_work_mem to '512 MB';
The `sqlite` command accepts the following clauses and options:
- *FROM*
Path or HTTP URL to a SQLite file, might be a `.zip` file.
- *WITH*
When loading from a `SQLite` database, the following options are
supported:
- *include drop*
When this option is listed, pgloader drop in the PostgreSQL
connection all the table whose names have been found in the SQLite
database. This option allows for using the same command several
times in a row until you figure out all the options, starting
automatically from a clean environment.
- *include no drop*
When this option is listed, pgloader will not include any `DROP`
statement when loading the data.
- *truncate*
When this option is listed, pgloader issue the `TRUNCATE` command
against each PostgreSQL table just before loading data into it.
- *no truncate*
When this topion is listed, pgloader issues no `TRUNCATE` command.
- *create tables*
When this option is listed, pgloader creates the table using the
meta data found in the `SQLite` file, which must contain a list of
fields with their data type. A standard data type conversion from
DBF to PostgreSQL is done.
- *create no tables*
When this option is listed, pgloader skips the creation of table
before lading data, target tables must then already exist.
- *create indexes*
When this option is listed, pgloader gets the definitions of all
the indexes found in the SQLite database and create the same set of
index definitions against the PostgreSQL database.
- *create no indexes*
When this option is listed, pgloader skips the creating indexes.
- *reset sequences*
When this option is listed, at the end of the data loading and after
the indexes have all been created, pgloader resets all the
PostgreSQL sequences created to the current maximum value of the
column they are attached to.
- *reset no sequences*
When this option is listed, pgloader skips resetting sequences after
the load.
The options *schema only* and *data only* have no effects on this
option.
- *schema only*
When this option is listed pgloader will refrain from migrating the
data over. Note that the schema in this context includes the
indexes when the option *create indexes* has been listed.
- *data only*
When this option is listed pgloader only issues the `COPY`
statements, without doing any other processing.
- *INCLUDING ONLY TABLE NAMES MATCHING*
Introduce a comma separated list of table names or *regular expression*
used to limit the tables to migrate to a sublist.
Example:
INCLUDING ONLY TABLE NAMES MATCHING ~/film/, 'actor'
- *EXCLUDING TABLE NAMES MATCHING*
Introduce a comma separated list of table names or *rugular expression*
used to exclude table names from the migration. This filter only applies
to the result of the *INCLUDING* filter.
EXCLUDING TABLE NAMES MATCHING ~<ory>
## TRANSFORMATION FUNCTIONS
Some data types are implemented in a different enough way that a
transformation function is necessary. This function must be written in
`Common lisp` and is searched in the `pgloader.transforms` package.
Some default transformation function are provided with pgloader, and you can
use the `--load` command line option to load and compile your own lisp file
into pgloader at runtime. For your functions to be found, remember to begin
your lisp file with the following form:
(in-package #:pgloader.transforms)
The provided transformation functions are:
- *zero-dates-to-null*
When the input date is all zeroes, return `nil`, which gets loaded as a
PostgreSQL `NULL` value.
- *date-with-no-separator*
Applies *zero-dates-to-null* then transform the given date into a format
that PostgreSQL will actually process:
In: "20041002152952"
Out: "2004-10-02 15:29:52"
- *tinyint-to-boolean*
As MySQL lacks a proper boolean type, *tinyint* is often used to
implement that. This function transforms `0` to `'false'` and anything
else to `'true`'.
- *int-to-ip*
Convert an integer into a dotted representation of an ip4.
In: 18435761
Out: "1.25.78.177"
- *ip-range*
Converts a couple of integers given as strings into a range of ip4.
In: "16825344" "16825599"
Out: "1.0.188.0-1.0.188.255"
- *convert-mysql-point*
Converts from the `astext` representation of points in MySQL to the
PostgreSQL representation.
In: "POINT(48.5513589 7.6926827)"
Out: "(48.5513589,7.6926827)"
- *float-to-string*
Converts a Common Lisp float into a string suitable for a PostgreSQL float:
In: 100.0d0
Out: "100.0"
- *set-to-enum-array*
Converts a string representing a MySQL SET into a PostgreSQL Array of
Enum values from the set.
In: "foo,bar"
Out: "{foo,bar}"
- *right-trimg*
Remove whitespaces at end of string.
- *byte-vector-to-bytea*
Transform a simple array of unsigned bytes to the PostgreSQL bytea Hex
Format representation as documented at
http://www.postgresql.org/docs/9.3/interactive/datatype-binary.html
## LOAD MESSAGES
This command is still experimental and allows to receive messages in UDP
with a syslod like format, and depending on matching rules load named parts
them to a destination table.
LOAD MESSAGES
FROM syslog://localhost:10514/
WHEN MATCHES rsyslog-msg IN apache
REGISTERING timestamp, ip, rest
INTO postgresql://localhost/db?logs.apache
SET guc_1 = 'value', guc_2 = 'other value'
WHEN MATCHES rsyslog-msg IN others
REGISTERING timestamp, app-name, data
INTO postgresql://localhost/db?logs.others
SET guc_1 = 'value', guc_2 = 'other value'
WITH apache = rsyslog
DATA = IP REST
IP = 1*3DIGIT "." 1*3DIGIT "."1*3DIGIT "."1*3DIGIT
REST = ~/.*/
WITH others = rsyslog;
As the command is still experimental the options might be changed in the
future and the details are not documented.
## AUTHOR
Dimitri Fontaine <dimitri@2ndQuadrant.fr>
## SEE ALSO
PostgreSQL COPY documentation at <http://www.postgresql.org/docs/9.3/static/sql-copy.html>.
The pgloader source code and all documentation may be downloaded from
<http://tapoueh.org/pgloader/>.
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