mirror of
https://github.com/dimitri/pgloader.git
synced 2025-08-08 07:16:58 +02:00
925996000b
Make it easier to nagivate our docs, which are dense enough to warrant proper organisation and guided Table of Contents.
231 lines
7.0 KiB
ReStructuredText
231 lines
7.0 KiB
ReStructuredText
SQLite to Postgres
|
|
==================
|
|
|
|
This command instructs pgloader to load data from a SQLite file. Automatic
|
|
discovery of the schema is supported, including build of the indexes.
|
|
|
|
Using default settings
|
|
----------------------
|
|
|
|
Here is the simplest command line example, which might be all you need:
|
|
|
|
::
|
|
|
|
$ pgloader sqlite:///path/to/file.db pgsql://pguser@pghost/dbname
|
|
|
|
Using advanced options and a load command file
|
|
----------------------------------------------
|
|
|
|
The command then would be:
|
|
|
|
::
|
|
|
|
$ pgloader db.load
|
|
|
|
Here's an example of the ``db.load`` contents then::
|
|
|
|
load database
|
|
from sqlite:///Users/dim/Downloads/lastfm_tags.db
|
|
into postgresql:///tags
|
|
|
|
with include drop, create tables, create indexes, reset sequences
|
|
|
|
set work_mem to '16MB', maintenance_work_mem to '512 MB';
|
|
|
|
Common Clauses
|
|
--------------
|
|
|
|
Please refer to :ref:`common_clauses` for documentation about common
|
|
clauses.
|
|
|
|
SQLite Database Source Specification: FROM
|
|
------------------------------------------
|
|
|
|
Path or HTTP URL to a SQLite file, might be a `.zip` file.
|
|
|
|
SQLite Database Migration Options: WITH
|
|
---------------------------------------
|
|
|
|
When loading from a `SQLite` database, the following options are
|
|
supported:
|
|
|
|
When loading from a `SQLite` database, the following options are
|
|
supported, and the default *WITH* clause is: *no truncate*, *create
|
|
tables*, *include drop*, *create indexes*, *reset sequences*, *downcase
|
|
identifiers*, *encoding 'utf-8'*.
|
|
|
|
- *include drop*
|
|
|
|
When this option is listed, pgloader drops all the tables in the target
|
|
PostgreSQL database whose names appear 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. Please note that `CASCADE` is used to ensure that tables
|
|
are dropped even if there are foreign keys pointing to them. This is
|
|
precisely what `include drop` is intended to do: drop all target tables
|
|
and recreate them.
|
|
|
|
Great care needs to be taken when using `include drop`, as it will
|
|
cascade to *all* objects referencing the target tables, possibly
|
|
including other tables that are not being loaded from the source DB.
|
|
|
|
- *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 option is listed, pgloader issues no `TRUNCATE` command.
|
|
|
|
- *disable triggers*
|
|
|
|
When this option is listed, pgloader issues an `ALTER TABLE ... DISABLE
|
|
TRIGGER ALL` command against the PostgreSQL target table before copying
|
|
the data, then the command `ALTER TABLE ... ENABLE TRIGGER ALL` once the
|
|
`COPY` is done.
|
|
|
|
This option allows loading data into a pre-existing table ignoring
|
|
the *foreign key constraints* and user defined triggers and may
|
|
result in invalid *foreign key constraints* once the data is loaded.
|
|
Use with care.
|
|
|
|
- *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 SQLite to
|
|
PostgreSQL is done.
|
|
|
|
- *create no tables*
|
|
|
|
When this option is listed, pgloader skips the creation of table before
|
|
loading data, target tables must then already exist.
|
|
|
|
Also, when using *create no tables* pgloader fetches the metadata
|
|
from the current target database and checks type casting, then will
|
|
remove constraints and indexes prior to loading the data and install
|
|
them back again once the loading is done.
|
|
|
|
- *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.
|
|
|
|
- *drop indexes*
|
|
|
|
When this option is listed, pgloader drops the indexes in the target
|
|
database before loading the data, and creates them again at the end
|
|
of the data copy.
|
|
|
|
- *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.
|
|
|
|
- *encoding*
|
|
|
|
This option allows to control which encoding to parse the SQLite text
|
|
data with. Defaults to UTF-8.
|
|
|
|
SQLite Database Casting Rules
|
|
-----------------------------
|
|
|
|
The command *CAST* introduces user-defined casting rules.
|
|
|
|
The cast clause allows to specify custom casting rules, either to overload
|
|
the default casting rules or to amend them with special cases.
|
|
|
|
SQlite Database Partial Migrations
|
|
----------------------------------
|
|
|
|
INCLUDING ONLY TABLE NAMES LIKE
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
Introduce a comma separated list of table name patterns used to limit the
|
|
tables to migrate to a sublist.
|
|
|
|
Example::
|
|
|
|
including only table names like 'Invoice%'
|
|
|
|
EXCLUDING TABLE NAMES LIKE
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
Introduce a comma separated list of table name patterns used to exclude
|
|
table names from the migration. This filter only applies to the result of
|
|
the *INCLUDING* filter.
|
|
|
|
::
|
|
|
|
excluding table names like 'appointments'
|
|
|
|
Default SQLite Casting Rules
|
|
----------------------------
|
|
|
|
When migrating from SQLite the following Casting Rules are provided:
|
|
|
|
Numbers::
|
|
|
|
type tinyint to smallint using integer-to-string
|
|
type integer to bigint using integer-to-string
|
|
|
|
type float to float using float-to-string
|
|
type real to real using float-to-string
|
|
type double to double precision using float-to-string
|
|
type numeric to numeric using float-to-string
|
|
type decimal to numeric using float-to-string
|
|
|
|
Texts::
|
|
|
|
type character to text drop typemod
|
|
type varchar to text drop typemod
|
|
type nvarchar to text drop typemod
|
|
type char to text drop typemod
|
|
type nchar to text drop typemod
|
|
type nvarchar to text drop typemod
|
|
type clob to text drop typemod
|
|
|
|
Binary::
|
|
|
|
type blob to bytea
|
|
|
|
Date::
|
|
|
|
type datetime to timestamptz using sqlite-timestamp-to-timestamp
|
|
type timestamp to timestamptz using sqlite-timestamp-to-timestamp
|
|
type timestamptz to timestamptz using sqlite-timestamp-to-timestamp
|
|
|
|
|