pgdiff

README

pgdiff - PostgreSQL schema diff

pgdiff compares the schema between two PostgreSQL 9 databases and generates alter statements to be manually run against the second database to make them match. The provided pgdiff.sh script helps automate the process.

pgdiff is transparent in what it does, so it never modifies a database directly. You alone are responsible for verifying the generated SQL before running it against your database. Go ahead and see what SQL gets generated.

pgdiff is written to be easy to expand and improve the accuracy of the diff.

download

osx   linux   windows

usage

pgdiff [options] <schemaType>

(where options and <schemaType> are listed below)

I have found that there is an ideal order for running the different schema types. This order should minimize the problems you encounter. For example, you will always want to add new tables before you add new columns. This is the order that has worked for me, however "your mileage may vary".

Schema type ordering:

1. FUNCTION
2. ROLE
3. SEQUENCE
4. TABLE
5. COLUMN
6. VIEW
7. OWNER
8. INDEX
9. FOREIGN_KEY
10. GRANT_RELATIONSHIP
11. GRANT_ATTRIBUTE
12. TRIGGER

example

I have found it helpful to take --schema-only dumps of the databases in question, load them into a local postgres, then do my sql generation and testing there before running the SQL against a more official database. Your local postgres instance will need the correct users/roles populated because db dumps do not copy that information.

pgdiff -U dbuser -H localhost -D refDB  -O "sslmode=disable" \
       -u dbuser -h localhost -d compDB -o "sslmode=disable" \
       TABLE 

options

options	explanation
-V, --version	prints the version of pgdiff being used
-?, --help	displays helpful usage information
-U, --user1	first postgres user
-u, --user2	second postgres user
-W, --password1	first db password
-w, --password2	second db password
-H, --host1	first db host. default is localhost
-h, --host2	second db host. default is localhost
-P, --port1	first db port number. default is 5432
-p, --port2	second db port number. default is 5432
-D, --dbname1	first db name
-d, --dbname2	second db name
-O, --option1	first db options. example: sslmode=disable
-o, --option2	second db options. example: sslmode=disable

getting started on linux and osx

linux and osx binaries are packaged with an extra, optional bash script and pgrun program that helps speed the diffing process.

1. download the tgz file for your OS
2. untar it: tar -xzvf pgdiff.tgz
3. cd to the new pgdiff directory
4. edit the db connection defaults in pgdiff.sh
5. ...or manually run pgdiff for each schema type listed in the usage section above
6. review the SQL output for each schema type and, if you want to make them match, run it against db2

getting started on windows

1. download pgdiff.exe from the bin-win directory on github
2. edit the db connection defaults in pgdiff.sh or...
3. manually run pgdiff for each schema type listed in the usage section above
4. review the SQL output and, if you want to make them match, run it against db2

version history

1. 0.9.0 - Implemented ROLE, SEQUENCE, TABLE, COLUMN, INDEX, FOREIGN_KEY, OWNER, GRANT_RELATIONSHIP, GRANT_ATTRIBUTE
2. 0.9.1 - Added VIEW, FUNCTION, and TRIGGER (Thank you, Shawn Carroll AKA SparkeyG)
3. 0.9.2 - Fixed bug when using the non-default port

todo

1. fix SQL for adding an array column
2. add windows version of pgdiff.sh (or even better: re-write it in Go)
3. allow editing of individual SQL lines after failure (this would probably be done in the script pgdiff.sh)
4. store failed SQL statements in an error file for later fixing and rerunning?