PostgreSQL to MySQL
real-time replication
TwinCommit replicates PostgreSQL to MySQL in real time by reading the PostgreSQL transaction log and applying every committed change exactly once and in commit order. Use it to migrate or continuously mirror PostgreSQL into MySQL with zero downtime, with no triggers or capture tables on the source.
PostgreSQL
log reader
commit-ordered · exactly-once
MySQL
native writer
How capture works on PostgreSQL
TwinCommit uses a logical replication slot with the built-in pgoutput plugin, so there is nothing to install on the server.
Prerequisites
- ✓wal_level = logical
- ✓REPLICATION privilege
- ✓Primary key or REPLICA IDENTITY FULL
How apply works on MySQL
Multi-row INSERT … ON DUPLICATE KEY UPDATE and DELETE batches, committed with the checkpoint in one transaction.
Requirements
- ✓binlog_format = ROW and binlog_row_image = FULL
- ✓GTID mode recommended
- ✓REPLICATION SLAVE and REPLICATION CLIENT grants
Setup
Set up PostgreSQL → MySQL in four steps
- 1
Prepare PostgreSQL
Run twincommit check. It verifies wal_level = logical and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at MySQL
Add a target block for MySQL. TwinCommit can generate target DDL with twincommit ddl -apply.
- 3
Snapshot
twincommit snapshot copies each table under a brief share lock and records the exact log position.
- 4
Stream
twincommit run streams every committed change from that position, exactly once and in commit order.
source:
type: postgres
dsn: ${SOURCE_DSN}
slot: twincommit
target:
type: mysql
dsn: ${MYSQL_DSN}
database: replica
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]PostgreSQL to MySQL replication FAQ
How does TwinCommit replicate PostgreSQL to MySQL?
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TwinCommit reads changes from the PostgreSQL transaction log, buffers them per transaction, and applies each committed transaction to MySQL in commit order. Multi-row INSERT … ON DUPLICATE KEY UPDATE and DELETE batches, committed with the checkpoint in one transaction.
Does PostgreSQL to MySQL replication need triggers or capture tables?
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No. TwinCommit reads the PostgreSQL log directly and creates no objects in the source database.
Is PostgreSQL to MySQL replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same MySQL transaction as the data, so a crash or restart never loses or duplicates a transaction.
What PostgreSQL versions are supported?
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PostgreSQL 13–18 · Amazon RDS and Aurora · Azure Flexible Server · Cloud SQL · AlloyDB.
Stream PostgreSQL to MySQL today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.