apgdiff

Overview

apgdiff turns differences between two PostgreSQL schema dumps into SQL for updating the older schema. It is best suited to developers and database administrators comfortable with terminal workflows who need a focused migration step. Its free, MIT-licensed model is appealing, but its selective SQL coverage makes review of every generated change essential.

Supply an original dump and a newer dump, then print the generated statements or redirect them to a file. That straightforward input-and-output workflow can fit batch jobs or web applications, but apgdiff compares dump files rather than serving as a broader database-management environment. It supports PostgreSQL alone.

The project offers binary and source ZIP downloads, and identifies version 2.4 as its latest stable release. The project news dates that release to 2012-09-21, a long gap that teams should factor into decisions about an evolving migration workflow. Bug reports and feature requests go through GitHub Issues.

Key features

Supported statements include selected ALTER SEQUENCE, ALTER TABLE, ALTER VIEW, COMMENT, CREATE FUNCTION, CREATE INDEX, CREATE SCHEMA, CREATE SEQUENCE, CREATE TABLE, CREATE TRIGGER, CREATE VIEW, and SET search_path statements. For schema changes built from those constructs, apgdiff can produce upgrade DDL that can be saved as a migration script.

This is a defined subset, not comprehensive SQL coverage: other statements are ignored. The --output-ignored-statements option reports DDL that apgdiff currently skips, which can help surface gaps before a migration is applied. CREATE TABLE column constraints are narrower still: only NULL and NOT NULL are supported. The usage guide recommends reviewing generated upgrade statements and, where appropriate, testing them on another database before production use. That caution is central to using apgdiff safely, not an optional final check.

As a Java program, apgdiff requires Java 1.6 or newer. Its homepage names Windows, Linux, Mac OS X, Solaris, and BSD, and says it can run on other systems with Java. The terminal interface suits command-line users and can be inconvenient for those who prefer graphical tools.

Pricing

apgdiff is free: its Free plan costs nothing and includes the PostgreSQL schema-diff tool under the MIT License. There is no paid tier or free-trial decision to weigh; the trade-off is the tool’s narrow scope and the care required to validate its output.

Platforms

apgdiff runs on Linux, macOS, and Windows, with Java 1.6 or newer required. Its homepage also names Solaris and BSD, as well as other systems where Java is available. This broad runtime reach is useful for terminal-based workflows, but does not change its single-engine focus on PostgreSQL.

Who it's for

Choose apgdiff if you work comfortably at a command line and need to generate PostgreSQL schema-difference statements from two dump files, especially as one step in a batch or web-application workflow. It is a weaker fit if you need a graphical interface, broad SQL coverage, or a tool with a more recent stable release.

Pros and cons

• Pros: Free and MIT licensed, with generated SQL that can be printed or saved as a migration script.
• Pros: The ignored-statement reporting option makes some coverage gaps visible during review.
• Cons: Unsupported statements are ignored, and CREATE TABLE column constraints cover only NULL and NOT NULL.
• Cons: Generated SQL needs careful review and potentially separate-database testing before production use.
• Cons: The terminal workflow may be inconvenient for non-command-line users, and version 2.4 dates to 2012.

Alternatives

Browse database schema comparison tools if you want to compare more options before settling on a PostgreSQL dump-based workflow.

Consider Skeema if you want a freemium option with a free Community plan covering tables, stored procedures and functions, and 18 linter checks; its Plus plan is $124 a month. Choose dbForge Studio for PostgreSQL if a freemium tool with a free, limited-functionality Express plan and a free trial better fits your evaluation; its Standard plan is $89.95 a year.

sqldef is another free, MIT-licensed command-line option for readers considering schema comparison tools. pgquarrel is a free, BSD-3-Clause-licensed alternative. dbdiff and DBDiff are also free alternatives. For a self-hosted option with a free plan and no accounts in default local mode, consider driftcurve. Redgate SQL Provision is a paid alternative with capacity tiers based on total production data volume to provision or mask; its price is custom pricing.

Verdict

apgdiff is a sensible pick for a technically comfortable user who needs a free, focused way to derive PostgreSQL upgrade statements from schema dumps. Its strongest reason to choose it is that direct, scriptable workflow; its strongest reason to look elsewhere is the selective coverage, which makes unreviewed output unsafe to treat as a complete migration.