This started as a quick hack some years ago, when I broke my PostgreSQL database (must have been version 7.3 or so) so that pg_dump wouldn't dump it anymore. Plus it couldn't handle dumping say only functions from certain schema. I have since then learned how to fix my database and pg_dump got options like --schema.

But the idea of a database being able to dump itself more autonomously persisted. After all, if LISP can do it, why not Postgres with its awesome SQL power? Information is all there in the system catalogs. One just needs to decipher it.

This tool uses information schema and standard SQL as much as possible, but for any actual practical use decoding of PostgreSQL system catalogs is required. Querying pg_catalog can turn out to be quite complicated for a somewhat casual SQL user. This project attempts to collect many SQL snippets made over the years into a coherent extension.

This will hopefully help to keep relevant SQL code for these things in one place. Perhaps this can also be of some use to GUI tools builders and such.


Support for other postgres objects: - pg_amop, pg_amproc - extensions

Support for other missing options: - PG 10+: partitions (subpartitions) - PG 10+: generated - comments on all objects - ownership of all objects - grants on all objects - grants vs current_role (who is grantor?) - materialized view tablespace & storage parameters - table of type (not null) - SET STATISTICS on indexes

Other: - figure out how to elegantly separate pre-data, post-data, create, alter and dcl - use ONLY when appropriate - move not nulls to constraints section - improve support for non superusers (more testing, etc) - improve dumping of comments (be quiet on NULL comments) Currently NULL comments are included, to encourage commenting. - handle dependancies for types better (use shell types) - do not emit ALTER OWNER for objects owned by current role - improve and add to simple tests - make some tests to test if what we output actually runs, test execute them - make some tests which compare to output of pg_dump; make utility for any sql file to compare the dump by pg_dump and ddlx. Comparison should compare actual contents, not merely text.


Some options as to what and how to dump stuff might be required:

CREATE TYPE pg_ddl_options AS (
  ddldrop  boolean, -- generate DROP statements
  ddlalter boolean, -- prefer ALTER to CREATE
  ddldcl   boolean, -- include DCL (GRANTS)
  ddlcor   boolean, -- CREATE OR REPLACE 
  ddline   boolean, -- IF NOT EXISTS
  ddlie    boolean, -- IF EXISTS
  ddlwrap  boolean, -- wrap in BEGIN / END
  ddldep   boolean, -- output objects which depend on this object too
  ddldata  boolean  -- add statements preserve / copy table data

Also, consider pre and post data DDL.

These might be passed as optional second arg to extractor functions Perhaps as a text array? JSON?

Perhaps there are other ways to implement some of this?

Other DDL dumping tools


Command line client psql contains lots of packaged SQL for handling metadata mainly to support code completion and various \d* commands.


Database dump tool pg_dump contains lots of packaged SQL for handling metadata and especially considers various dependancies. Source code for main C source file is is about 20000 lines long.


PgAdmin3 DDL generation and schema handling code is an interesting mix of wxWidgets GUI toolkit (C++) and SQL. It requires GUI. Generated DDLs are database administrator friendly.


PgAdmin4 is the stuff of legends

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