How to Migrate from On-Premise PostgreSQL to MariaDB

Galaxy Glossary

How do I migrate my on-premise PostgreSQL database to MariaDB?

Export PostgreSQL data, transform incompatible types, and import into MariaDB with minimal downtime.

Welcome to the Galaxy, Guardian!

Oops! Something went wrong while submitting the form.

Description

Example H2

Example H3

Why migrate from PostgreSQL to MariaDB?

MariaDB can reduce licensing costs, simplify replication setups, and integrate easily with MySQL-compatible tools. Moving from on-premise PostgreSQL to MariaDB also eases cloud adoption because most managed databases support the MySQL protocol.

Which migration path fits my needs?

Small databases (<10 GB) work well with CSV exports and LOAD DATA INFILE. Larger sets benefit from logical replication tools like pg_chameleon, while near-zero-downtime moves combine pg_dump for initial load with CDC tools (e.g., Debezium) for catch-up.

How do I check type compatibility?

List all PostgreSQL column types and map them: BOOLEAN → TINYINT(1), TEXT → LONGTEXT, UUID → CHAR(36), TIMESTAMPTZ → DATETIME. Create staging tables in MariaDB with compatible types before import to avoid runtime errors.

What’s the safe export syntax?

Use pg_dump with --column-inserts or CSV format. The latter produces faster imports because MariaDB can bulk-load files.

# full CSV export pg_dump -h 192.168.1.10 -U admin -F c -t Customers -t Orders -t Products \ --data-only --file=ecom_backup.dump ecommerce # single table CSV psql -h 192.168.1.10 -U admin -d ecommerce -c \ "\COPY Customers TO 'customers.csv' CSV"

How do I import into MariaDB?

Copy exported files to the MariaDB server. Then bulk-load:

LOAD DATA INFILE '/var/lib/mysql-files/customers.csv' INTO TABLE Customers FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY '\n';

How do I verify data integrity?

Run row-count checks: SELECT COUNT(*) FROM Customers; in both systems. Spot-check totals (SUM(total_amount)) on Orders. For strict validation, hash full tables with MD5(GROUP_CONCAT(...)) and compare.

How can I cut over with minimal downtime?

1) Freeze writes on PostgreSQL. 2) Export delta via logical replication or WAL2JSON. 3) Apply deltas to MariaDB. 4) Update application connection strings. Keep PostgreSQL read-only for rollback.

Best practices for a smooth migration?

• Migrate least critical tables first.
• Disable foreign-key checks during bulk load (SET foreign_key_checks = 0;).
• Enable binary logging after import to keep backups consistent.
• Index after loading to speed inserts.

Common mistakes to avoid

Data type mismatch: Failing to convert NUMERIC to DECIMAL causes silent truncation. Map types explicitly before import.

Ignoring time zones: PostgreSQL stores TIMESTAMPTZ in UTC, but MariaDB’s DATETIME is naive. Convert to UTC strings during export to keep timestamps correct.

Quick checklist before production cutover

✔️ Schema recreated in MariaDB
✔️ All tables loaded and validated
✔️ Triggers, defaults, and constraints re-implemented
✔️ Application connection strings switched
✔️ Rollback plan documented

Why How to Migrate from On-Premise PostgreSQL to MariaDB is important

How to Migrate from On-Premise PostgreSQL to MariaDB Example Usage


-- After migration, verify total spend per customer in MariaDB
SELECT c.name,
       SUM(o.total_amount) AS lifetime_value
FROM Customers c
JOIN Orders o ON o.customer_id = c.id
GROUP BY c.id, c.name
ORDER BY lifetime_value DESC
LIMIT 10;

How to Migrate from On-Premise PostgreSQL to MariaDB Syntax


# Export selected tables from on-premise PostgreSQL
docker exec -it pg_container pg_dump -U admin -h 192.168.1.10 \
  --data-only --column-inserts --table=Customers \
  --table=Orders --table=OrderItems ecommerce > data.sql

# Create equivalent tables in MariaDB
CREATE TABLE Customers (
  id INT PRIMARY KEY,
  name VARCHAR(100),
  email VARCHAR(255),
  created_at DATETIME
);

CREATE TABLE Orders (
  id INT PRIMARY KEY,
  customer_id INT,
  order_date DATETIME,
  total_amount DECIMAL(10,2)
);

# Import into MariaDB
mysql -u root -p ecommerce < data.sql

# Bulk-loading CSV (faster)
LOAD DATA INFILE '/var/lib/mysql-files/products.csv' 
INTO TABLE Products 
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' 
LINES TERMINATED BY '\n' 
(id, name, price, stock);

Common Mistakes

Relying on AUTO_INCREMENT during bulk load. Fix: Insert explicit primary keys, then re-enable auto-increment to avoid gaps.
Copying BLOB columns as text. Fix: Export BLOBs with bytea escape format and import using MariaDB’s proper BLOB types.