PostgreSQL to Synapse
real-time replication
TwinCommit replicates PostgreSQL to Azure Synapse Analytics in real time by reading the PostgreSQL transaction log and applying every committed change exactly once and in commit order. Use it to feed Synapse with live PostgreSQL data for analytics, AI and reporting, with no triggers or capture tables on the source.
PostgreSQL
log reader
commit-ordered · exactly-once
Synapse
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 Synapse
Micro-batches are staged as Parquet in Azure Data Lake Storage, loaded with COPY INTO and applied with MERGE in one transaction together with the checkpoint. Tables are created hash-distributed on the primary key.
Requirements
- ✓An ADLS Gen2 staging container
- ✓A service principal or managed identity with db_ddladmin and db_datawriter
- ✓ADMINISTER DATABASE BULK OPERATIONS for COPY INTO
Setup
Set up PostgreSQL → Synapse 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 Synapse
Add a target block for Synapse. 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: synapse
server: acme-dw.sql.azuresynapse.net
database: replica_dw
auth: managed_identity
staging: abfss://staging@acmelake.dfs.core.windows.net/twincommit/
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]PostgreSQL to Synapse replication FAQ
How does TwinCommit replicate PostgreSQL to Synapse?
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TwinCommit reads changes from the PostgreSQL transaction log, buffers them per transaction, and applies each committed transaction to Synapse in commit order. Micro-batches are staged as Parquet in Azure Data Lake Storage, loaded with COPY INTO and applied with MERGE in one transaction together with the checkpoint. Tables are created hash-distributed on the primary key.
Does PostgreSQL to Synapse 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 Synapse replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same Synapse 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 Synapse today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.