PostgreSQL to ADLS
real-time replication
TwinCommit replicates PostgreSQL to Azure Data Lake Storage in real time by reading the PostgreSQL transaction log and applying every committed change exactly once and in commit order. Use it to land live PostgreSQL data in ADLS as open Delta Lake or Iceberg tables, with no triggers or capture tables on the source.
PostgreSQL
log reader
commit-ordered · exactly-once
ADLS
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 ADLS
Each micro-batch becomes one atomic Delta Lake or Apache Iceberg commit (or Parquet files) with the checkpoint stored in the commit itself. Use merge mode to mirror current state, or append mode for a full change history.
Requirements
- ✓Storage Blob Data Contributor on the container
- ✓Hierarchical namespace enabled
- ✓Optional Iceberg catalog (REST or Hive Metastore)
Setup
Set up PostgreSQL → ADLS 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 ADLS
Add a target block for ADLS. 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: adls
account: acmelake
container: lake
path: replica/{schema}/{table}
format: delta
mode: merge
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]PostgreSQL to ADLS replication FAQ
How does TwinCommit replicate PostgreSQL to ADLS?
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TwinCommit reads changes from the PostgreSQL transaction log, buffers them per transaction, and applies each committed transaction to ADLS in commit order. Each micro-batch becomes one atomic Delta Lake or Apache Iceberg commit (or Parquet files) with the checkpoint stored in the commit itself. Use merge mode to mirror current state, or append mode for a full change history.
Does PostgreSQL to ADLS 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 ADLS replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same ADLS 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 ADLS today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.